Hmm... what about this?

Orchard of Tainted Bliss
Creature - Demon Plant
, pay 1 life: Add one mana of any color. Put a deal counter on ~.
At the beginning of your upkeep, you may remove three deal counters from ~. If you do, create a black and green 1/1 Devil Dryad with reach and lifelink.
You will never desire anything else.
0/3

There's some Utopia Mycon mixed in there, now that I think of it. More possible inspirations for an entry:

Virulent Porcupine
Creature - Beast
Whenever a creature deals damage to ~, put a -1/-1 counter on it.
When ~ dies, proliferate.
"Its ability would suggest a spiteful attitude, but every observed specimen appears to be strangely placid."
1/3

Relentless Burrower
Creature - Zombie Wurm
~ attacks each combat if able.
When ~ dies, sacrifice a land. If you do, put it unto the battlefield at the end of turn.
Constantly feeding, yet never sated.
5/1

I imagined a living, version with haste (and possibly trample) that burrowed into innocent lands by exiling itself and returning next turn, but I found no clean wording for that.

?????
Legendary Creature - Demon Treefolk R
, pay 1 life: Add one mana of any color to your mana pool.
, pay 2 life: Draw a card.
"Forbidden fruit tastes the sweetest, that's why they don't want you to have it."
3/6

Diabolic Dryad
Creature - Devil Dryad U
Haste
If you lost life this turn, Diabolic Dryad cannot be blocked.
"Come with me to the garden..."
1/1

While I think this works really well for flavor, I do think it might just be easier to give it Wither as a keyword.

Yeah, I don't think Quint would really be interested in undeath. A mild observation once to kind of understand the biological processes that might be going on, but he's no necromancer.

Loving some of the creativity. I'll pull up a few more hopefully odd and interesting creatures

Wurm King

Creature - Wurm
Wurm Offering
Trample
If a creature was sacrificed to cast Wurm King, Wurm King enters the battlefield with a number of additional +1/+1 counters equal to that creature's power.
8/8

Wretched Cannibal

Creature - Human Beast Horror
When Wretched Cannibal enters the battlefield or attacks, exile a creature card from your graveyard. If you do, put a +1/+1 counter on Wretched Cannibal. Otherwise, sacrifice it.
3/2

Forgotten One

Creature - Gremlin
Whenever Forgotten One blocks, becomes blocked, or becomes the target of a spell or ability, it phases out.
Whenever Forgotten One phases in, each opponent discards a card.
1/3

Shrieking Skyterror

Creature - Bat Bird
Flying
When you cast Shrieking Skyterror, if you spent 1 or less mana to cast it, draw a card
Creature spells you cast named Shrieking Skyterror cost less to cast.
A deck may have any number of cards named Shrieking Skyterror
1/1

There are times when success can often be worse than failure and in such times, failure can often occlude one’s insight into why something is, perhaps, not a terribly good idea to pursue. Unfortunately, failure has a way of galvanizing me to action, and repeated failure causes my more bullish tendencies to rear their heads. It becomes a matter, not of pride exactly, but vindication to see an idea through to the end. To have a hypothesis proven feasible more than correct.

The creature I’ve since dubbed the “Phoenoxatrice” is a perfect example of hubris outpacing common sense.

The experiment began with the initial study of Aves Ornignis, the firebirds known as Phoenixes. The study was a broad observational study of sample IKO114, originally looking into the energy source of the creatures’ infamous fire, but eventually landed on the Phoenix’s unique survival capability. It is well known that the birds are nigh immortal, their last breath causing a massive conflagration that cremates their mortal remains, and a new iteration rises from the ashes of the old. Despite the surprising rarity of Phoenixes in the multiverse, there is a shocking breadth to the adage of “rising like a phoenix from the ashes” indicating that despite their sparse numbers, there must be something to them.*

It was the ash, ultimately, that I stuck upon as a method of synthesis. Could it be possible to introduce foreign ash to the sample and fully hybridize the creature? That was my hypothesis and I prepared the experiment.

The first step was in finding a creature with a genotype close enough for compatibility. I considered griffins, rocs, and any number of other choices, but I ultimately landed on the Cockatrice (sample M14094) for my secondary subject. Early experimentations indicated that the freshness of the ash was critical and the cockatrice was not only a good match, but could provide the death trigger necessary for the conflagration, causing the immolation of both subjects in a single moment!

It was beautifully, elegantly neat, a self-contained methodology.

And it didn’t work. Repeatedly.

After no fewer than 62 trials, I had become stubborn. The symmetry was far too good and I was convinced that it must work, not merely that it could work. Upon the execution of trial 63, I was proven brilliantly correct. It was possible. And doing so was a stupid idea in the first place.

You see, what I hadn’t considered is what outcome I might actually be left with. That is… a nigh unkillable chicken with a death glare.

What’s more, while the stone gaze of a cockatrice is well known, the Phoenoxatrice did not merely turn it’s prey to stone. There was a unique interaction with the phoenix’s flames and the cockatrice’s gaze which meant that instead of being merely deadly, it was a visually directed flash carbonization of extreme heat that the end result possessed. The equivalent of a squawking, flying volcano, essentially.

After another 62 trials of trying to kill the creature, the most successful being drowning, until the creature detonates and displaces the water… I have given up. I have, instead, attempted my best (through proxy) to train the thing and intend fully to leave it be. Being able to take flight, I can only assume it has found a nest elsewhere that suits its needs better than my island.

Addendum: I have come to learn that there is a fascinating recent discovery about how phoenixes fully reproduce, in such a way that their numbers increase. As it would seem, a pregnant phoenix will essentially detonate in the air, scattering tiny meteoroids. The phenomenon has long been observed and is one of the few times when the ashes will disperse to the point that another bird will not rise from them. These meteoroids are actually eggs, and will hatch in short order, warmed by the deathly conflagaration.

The creature I’ve since dubbed the “Phoenoxatrice” is a perfect example of hubris outpacing common sense.

The symmetry was far too good and I was convinced that it must work, not merely that it could work. Upon the execution of trial 63, I was proven brilliantly correct. It was possible. And doing so was a stupid idea in the first place.

Dude, wasn't the name horrid enough to be a warning? Also, elegant turn of phrase there

I agree on the symmetry, I find the method very neat - and the last sentence had me cackling.

That Quint just leaves the resulting abomination free makes me want to both laugh and slap some sense into the man, gogdammit In an unrelated note, I find the phoenix' reproduction a pretty intriguing concept.

Thank you for sharing!

(you have an asterisk at the end of the "rising from the ashes" reference that I'm not sure what's supposed to point at?)

This latest entry reminds me of a moment from the old Fraggle Rock show that I think about often when it comes to eccentric inventors. The Inventor had been trying throughout the episode to figure out how to sew a button on a fried egg. In one scene, we hear his half of a phone conversation with a friend of his where he is explaining his current experiment. The Inventor pauses (listening to the comments of his friend on the other side of the conversion) and then grows visibly upset, and says, "What do you mean 'why?' I haven't even figured out how yet!"

I know it was "just" a kid's show, but I always thought that was a great indictment of some scientific minds. The sentiment was repeated by Jeff Goldblum's character in the original Jurassic Park film when Malcolm says, "your scientists were so preoccupied with whether or not they could that they didn't stop to think if they should."

Quint in general, and in this instance specifically, seems to suffer from the same sort of impulse.

Thesis: The affliction commonly known as Vampirism is not traditionally a biological virus or some form of parasite, but while the root source could be considered a curse, similar to lycanthropy, it displays inherent biological alterations that can be studied. I try not to foray often or extensively into matters of the spirit, as something less tangibly observable, it carries with it philosophical weight that I do not feel appropriately qualified to assess. The effects there of, however, are physical and can be measured.

What I find most peculiar is the consistent pattern across worlds of those afflicted. Despite the obvious differences in origin and what must be changes of a specific nature, the overwhelming log of data shows a shocking baseline that beggars belief. Of these many and myriad commonalities, the one that is most confusing, yet most prevalent, is the chiropteran features so associated with the curse.

But, my inquiry thus is what would occur if the curse is introduced to a non-standard subject, and one most especially that shares no possible commonality with the common bat. What, then, would happen?

To test this, I have collected samples of infected blood: M11082, STX166, VOW098, ZEN093 and run them through an alchemical purification using sample M20004 as a base with a method taught to me by a fellow planeswalker to create as pure a strain as possible. This should mean that no outside genetic components will influence the mutagenic properties inherent to the curse.

Subjects:There were three isolated tests that I performed in the wild. While normally, I prefer to control variables that the environment might introduce, I felt the need to monitor behavior outside such a controlled environment. Further, I suspect that environmental factors in each unique case may lead to greater varieties of dimorphism from the subject’s initial form. Below are the recorded observations for each subject.

JOU056: The subject’s exposure caused an immediate reaction, panic followed by a lethargy that set in shortly thereafter. It took approximately a fortnight before the full effects of the exposure came to pass. The scales of the subject sloughed off, exposing a rubbery hide and the face altered dramatically, taking on aspects of lamprey eels. The subject’s wits seemingly diminished substantially. Given the shallow existence it afforded, it spent a good deal of time burrowing into the sand to avoid the rays of the sun, but once disturbed would feed on any creature within reach. I cannot ultimately tell if the decline of cognition was due to an alteration in base behavior, or if the creature was merely dumbstruck by hunger, but the experiment ended abruptly after slightly less than a month’s observation when it made its day shelter in an area where low tide would prove fatal.

M11063: The subject of this portion of the experiment was exposed further out into the ocean and observation was made remotely and through secondary means. The change came far sooner than the previous instance, only something akin to 48 hours after infection. Similarly to the previous case, the scales shed, though from initial observations, the hide took on a form more resembling a Carcharodon. This transformation continued to bear true, as the eyes became full black, musculature increased, and dentation showed heavy redundancy. The nasal function also increased exponentially, though the gills present along the subject’s rib cages altered.

Subject demonstrated highly increased aggression, but interestingly, showed no sign of needing sleep so long as it remained fed. As the sun rose, it would merely retreat to the deeper depths and surface during eventide.

This subject, being more inherently humanoid displayed more traditionally vampiric qualities, though the exact features seem more intrinsically adapted to hunting. Further, the limitations of the sea’s prey meant that, unlike the previous subject, it fed almost exclusively cannibalistically, rather than partaking in whatever creature happened across.

It is my belief that this incarnation may provide further talents as it adapts, as seen in more traditional vampiric afflictions. A follow up will be necessary.

SHM165: The adaptation of the deepest specimens yet. Not by design, but there was exposure to two subjects during this attempt. Their forms almost immediately began to change, eyes enlarging, jaws shifting, long teeth developing more needlelike than the saws of the previous instances. The most fascinating part was the mutation to a bioluminescent number of ilicium at the ends of the fins. These unique features seem to be a derivative of a vampire’s hypnotic abilities, or perhaps an extension of the vampiric glamour.

Unfortunately, the study on these subjects was cut abruptly short given the difficulty of observation. What’s more, I feel that they became aware of being watched, and intentionally fled. Given the murky depths that they fled to, there was relatively little data collected.

On my way to the Kaposhan Sea to gather specimens of the unique Drake there, I made a detour to the Kalonian Forest to check on a creature I had unwittingly created. The locals call it an Ursoth, but l view it as a learning experience. Or, more directly put, an unintentional error.

You see, my original intention had been to try to revive a species known as the Onakke. They had quite a fascinating history from what I understood, and their ruins were rather spectacular. After I revivef one of them, I felt I could assess if their kind would be with bringing back to the multiverse, albeit relocated somewhere for a fresh start.

As all I had to work with were skeletons, I was left with a need to bridge the remaining gap in their creation, a host genome to give me something more fitting to clone and work with.

There was, however, one problem. I had been previously informed they were trolls.

The resultant creature was... Not as I had expected. While I could call it clever, I couldn't call it intelligent. I could hardly call it sentient. It was possessed of a cunning however, and given the nature in Kalonia, I didn't worry that it would cause much of a dent in the ecology.

Upon arrival in the forest, I saw no trace of the Ursoth. There was, however, something unsettling in the forests. The creatures were subdued, anxious. Something had clearly come to Shandalar that upset the balance of the ecosystem, and as I searched, I had the eerie knowledge that something or somethings was watching me. Several times, I caught sight of shadowy figures stalking through the trees, but the shadows made little sense, sometimes humanoid, other times seemingly quadrupedal.

As much as I would have liked to study the Ursoth in it's full maturity, I decided to move along to the sea to fulfill my original goal. Unfortunately, I could find few instances of the famed Kaposhan drakes either in the sky or the sea. Reluctantly, I decided to move on, but as it so happened, at that moment I stumbled upon something truly extraordinary.

I found a fascinating fossil half buried in the sand asking the beach. Unearthed, I could more clearly see the creature, and it was something utterly unique, a rarity for me. I have brought it back to the lab and sequestered it away for a more opportune time to study the remains and possibly bring an example of the species back to life.

I've dubbed the fossil sample TSP256 and placed it in the ossuary. As disappointing as the trip had been, I'm glad it didn't amount to nothing. Sometimes, fortune does smile upon the unlucky.

It’s been several days since my arrival in Skysail and the migratory patterns of the creature popularly known as Yorion has been a harrowing experience for most of the individuals here, but I have found it absolutely fascinating. The serpent’s adaptation to the upper atmosphere recalls a world I have heard of that has no land. Just an endless Sea of Clouds for as far as the eye can see, though interestingly, from what I gather, mana still manifests as might traditionally be expected. Once the season is over, I may attempt a sojourn there, though I’ll likely have to ask around the pub for any location I can glean.

The only other noteworthy thing to note as worthy, is… for lack of a better way to say it, I believe I am being followed. Thinking on it, that may not be the best way to put it, but I have seen something out of the corner of my eye. Many times, now that I fully consider the matter.

I can only really describe what I have seen as creature, something resembing a gremlin, or otherwise very similar. Its presence seems almost illusory, never fully seen and only in the periphery. I’ll admit, the first few times earlier this week, I thought nothing of it, thinking perhaps it was the altitude at work.

All harmless enough, but… I’ve started noticing damage to the areas that I frequent.

As I am an outsider, suspicion has quickly fallen upon me, and truthfully I do share their sense of worry, given the rather precipitous nature of their settlement, if it can even be called as such. A great tangle of bridges and buildings all held aloft by balloons and airships, tossed to the mercy of the winds? It’s a frightful thought to consider what may happen.

~~~~~~~~~~~~

The damage is growing worse, and the populace is rightfully growing agitated. Accusations are starting to be lobbed in my direction, but the damage is not easily matched to anything a human could accomplish and reluctantly, the inhabitants seem to agree. I don’t blame them for trying to find someone to blame. Having cleared my reputation, as best could be, I did bring up the possibility of the creature, even going so far as to describe the thing I have fleetingly glanced upon. The strangest thing is that my suggestions were all summarily dismissed.

Further oddity, now that I am aware there may be something skulking in the shadows, is that there have been several times I sensed the creature, yet when I turned to look, it was not there. That in itself, follows the pattern established, but what is strange is that the places I’ve seen the thing were in full view of others, and yet… nobody else seems to have seen it. Even, or especially, when they should have.

My usual curiosity is starting to wane, and my normally docile nature cannot shake an impending sense of dread about the matter.

~~~~~~~~~~~~

At first, I believed it my imagination. However it has been several days of this now, and I begin to doubt my senses. I am… growing anxious.

Beyond the ever mounting unease I feel, and the swiftly escalating degree of damage, I have started to wonder if I am becoming unmoored. I have been around for far longer than mortal men were meant to, and I am dearly aware of the results of exposure to epochs beyond such ken. Walkers as old as I, or even younger, have fallen to a madness, but I do not know if I should even question that I am mad? Would one know to ask of it?

If not for the evidence at hand, I’d worry that I was wrong about the whole affair. That I was truly seeing that which was not there. I am uncomfortable with such introspection at my own sanity.

~~~~~~~~~~~~~~

Plans are being made to evacuate this portion of the flotilla. I have collected my things and plan my own departure shortly. To this day, nobody believes in the creature I describe, none others have sighted it, and despite the obvious effect it has had, everyone seems to refuse the possibility.

They will not even entertain the thought, and I am at a loss for why.

I’ve come to the conclusion that I am not mad, that what I have seen is real and not a figment. Even as I write this very line, I am confident that the creature staring at me from the porthole is real. I believe it is responsible for the terror of the townsfolk, and that whatever phenomenon exists that keeps it from observation is also what makes them so adamant for its inexistence.

Why, then, it does not work on me, I shall never know.

As fascinating as I find studying the creature might be, that seems… highly improbable. Further, the environment is too precarious for my liking. I hope that it stays in its habitat and leaves me to mine, as I shudder to think what it may be capable of if it should follow me home.