This might seem obvious or not worth thinking about to some of you but here is my argument. As a college student interested ecology and biology, the ecosystems of planes that have giants, dragons, beasts of colossal sizes etc. don't seem to be sustainable. Ignoring everything else like Cube's Law, from what I can see the environments needed to sustain such truly colossal creatures do not exist. Oh they are forests that seem suitable

But not every forest looks like that, and such inadequate forests are often coupled with giant creature cards that in lore that have no business living there. And since Creative has gone on record saying that just because it doesn't appear as a card doesn't mean it's not there there is a good chance there are more colossal beast species living on any one plane like

It may be because of the art or maybe because I'm overthinking this but I think lands in lore look a lot like this.





Feel free to not comment if I'm being irrelevant.

Beasts like Craterhoof Behemoth strike me as the kind of creature that spends a vast amount of time in hibernation (to the point where it might be mistaken for a hill or something), and only becomes active for a short time to either eat or mate before falling into a deep sleep for years again at a time. Because....you just can't have a society where enormous beasts of such size constantly muddle through things....or at least I would have thought that until Kaladesh called out actually building around such beings. (By the way, what happens when a skywhale dies? What if it crashes into a city when it gets too old to stay aloft?)

But yeah, most mega-fauna beyond your basic dragon, hydra, or leviathan probably exist but are not super active.

That still leaves several mega fauna species including wurms that need food every other day or everyday to survive.

I don't know about Wurms. I assume they function similarly to snakes where they eat a big thing once and slowly digest it over a few days or weeks. Theoretically, you should be more interested in the herbivorous mega fauna since the larger carnivores would just prey on them and the plant eating needs is what would destroy a local ecosystem.

Oh I was thinking about them too believe me. I mentioned wurms because you didn't mention them. However, no matter how you slice it, you cannot have big creatures such as these living in the kind of environment usually depicted in .

Well...I mean, you can (this crap happens in D&D all the time under the purview of a Wizard or some other powerful entity "doing it")...

If you have some specific monsters from specific planes in mind we could talk about them better. I assume most mega-fauna from Theros are a god's fault. Nya and Jund are built for mega-fauna...etc.

The Theros lore actually mentions tales of endless forests beyond the mountains where giants and I assume other colossal creatures dwell. Nylea has gone on record saying she has gone on many trips to those forests and seen incredible things.

Tarkir has a number of beasts that are bigger than entire castles that are often used by the Abzan and the Sultai. The former lives in the desert which is the environment that has a hard time sustaining small creatures. And there are atleast one species of insect, Amubush Krotiq that is bigger than they. Insects are not capable of hibernating I Think. They reduce they're activity yes, but they do not go into a slumber. Temur dragons eat so much that mammoths and even most bears died out sometime ago which tells me that the environment is not big enough to sustain them.

Ravicna does not even have true forests or abundant flora in general and yet giant sentient and non-sentient creatures dwell there.

The Krosan forests depicted many colossal beasts. So much so that even if they do hibernate and wake up to eat and ****, there would barely be anything flora or fauna left to eat by the time there done.

As a side note, craterhoof behemoth strikes me as a herbivore, and most herbivores do not hibernate. Yes there's sharp teeth in his mouth, but what fauna is that monstrosity going to eat. Rule of 10: For every one carnivore there must be 10 herbivores to sustain it.

I think you are all underestimating the magic factor here. In a real world ecosystem of course these massive creatures couldn't be sustained but I always assumed that some part of them was sustained by magic. Dragons don't just eat cows, they are sustained by red mana to some degree. This is also how they create fire instead of relying on internal organs that generate incendiary chemicals. When you think about how much fire a dragon breathes, that's a LOT of energy expenditure so chemical production isn't likely, especially with how much fire dragons are recorded as producing.

Large megafauna may also need a generally higher oxygen level in the air, making the plane inhabitable to humans. I assumed that these creatures were generally sustained by green mana, which is partly what fueled and maintained their growth. Sea leviathans would get the same treatment as other megafauna, but are sustained on some level by blue mana instead.

As far as "eating everything ever" the answer is, again, green mana accelerating the growth rate of the plants to compensate.

I hate giving the old "a wizard did it" kind of answer but it's really the only plausible answer for such hyperecosystems. I also don't think that the majority of these creatures hibernate for massive periods of time. We have a few flavour text mentions of large creatures sleeping through battles but I think most of these creatures naturally dwell in the largest forests where there's more green mana to sustain them. This is why these massive creatures don't wander towards cities - there's a critical resource scarcity for them in those cities.

Unless shaped by some being or entity, the mana, while far reaching, only has nominal influence on any particular plane/universe. Much like how aether has a role on every plane but otherwise doesn't interact much in any significant way. Yes I can see red mana for the most part fueling draconic power, blue mana fueling a sphinx's innate abilities, green mana allowing for the existence of colossi. But when it comes to actually sustaining the creatures and making sure the ecosystem thrives green mana has little to no influence. Therefore the ecosystem is subject to very little magical interference and is subject to the laws of ecology. An example, the ecosystem in Tarkir's Temur region is slowly collapsing because they are too many megafauna with insatiable appetites eating everything. Yes, green mana does cause some flora to grow spontaneously in the form of Evolving wilds on that plane, but that is only slowing the collapse. The ecosystem just can't sustain it. Same thing happens even when magical interference is present in a big way. In the Odyssey Arc-Yes I know it was bad and got so retconned so much even the characters got sick of it-the bald guy-forgot his name-attempted to "help" the Krosan Forest with green magic. His actions later caused large swaths of the forest to turn into swamp later on.

So yeah, I don't like the "A wizard did it" argument either.

For the most part, Wurms aren't THAT large.
The biggest species we've seen are on both Ravnica and Zendikar, but otherwise, they're smaller than Hellions.

Regarding Krosa, you must keep in mind that the Mirari is directly responsible for most of the overgrowth there.

That just means they'll be more of them slithering around.

Exactly. Magical Interference caused the Whole system to collapse.

You'd be wrong about that. Alara is a perfect example of the very prominant way mana has a direct influence on an ecosystem. And it's not an isolated case either.
Garruk is over 8 FEET TALL. We've seen his father and even him as a young man and there's no way that sort of growth is natural. The only thing we can infer is an exposure to years of green mana made a giant out of him.

And it does follow a certain pattern that supports that.


That's not as accurate as you might suspect. The dragons themselves are an invasive, non natural species. They aren't, themselves, part of the ecosystem balance, so of course their presence is wreaking havoc. They're born out of spirit dragon farts, and while he slept everything got substantially worse, but it's not like they had a natural niche in the first place.

Totally to forgot to respond to the skywhale thing. Yeah I guess they fall on some somebody or something.

Truth on the first point about Alara and on Garruk-though I didn't know he was 8 feet tall. It's why I didn't mention Alara, Theros, Shandalar or Zendikar for that matter. But not every plane is a Alara, Theros, Shandalar or Zendikar. What I am doing is pointing out inconsistencies with colossi and megafauna appearing on worlds with comparably less magical influence or magical influence in different ways with ecosystems that don't seem to be able to sustain them.

Truth again. However like I said, I simply pointing out consistencies. In that same plane, Abzan are using natural giant colossi as their war beasts and "horses". Yet these beasts live in a desert. Magic may allow megafauna to exist, but it's not gonna feed the creatures. Garruk may have grown to 8 feet with magic influence, but he didn't feed on magic. The "Magic" hand wave-and that's exactly what is-can be used to explain away the small stuff but not everything.

Yeah, it's absolutely bonkers. Kinda freaked everyone out when they first dropped it on us.

I mean, you have some points about that, but we also don't know what kind of extent it is or isn't there. It's mostly something we can't directly observe, but we do know mana has a direct effect on creatures, even outside actual shaped spells. There was an entire portion of Urza's bloodline projects regarding it.

The deserts aren't even something you can lay at Magic's feet though. That's at least partially Frank Herbert's fault (probably.) Giant sand wurms paved the way for the rest of that.

As far as magic as a substitute for fod, there have been times, though always intentional in design. Serra's Realm functioned that way, but when we get down to it, there are a lot of unknowns in the discussion.

I'd also point out from the Mirrodin block books that when the green sun emerged it twisted a lot of creatures that were near it's egress. I remember Glissa (I almost called her Nissa, whoops) being appalled at the way a boar had been super sized but not its legs so it couldn't support its own weight. I imagine a much gentler, constant exposure to green mana from living in a forest would allow for a gradual adaptation to low levels of mana radiation.

All I'm saying is that if they're gonna put hyper megafauna on their planes they have to be paired with the a suitable ecology for them to live in. In Kaladesh, aether whales feed on aether and I suspect aether leviathans feed on them.

On Theros, they are endless forests that that I imagine are so big that even grass itself is huge.



I have seen forest arts of Zendikar depicting whole villages and cities living on a single branch.

So yeah, it can be done. Like they always say, MTG is a fantasy not a science fiction so no aliens from other planets in the plane.

P.S. If your wondering where I'm getting these pictures from don't ask. The artist, while he makes some very good landscapes is a major vore fetishist. For every picture with awesome backgrounds, there are ten with the background...and a 100 foot tall naked female giant eating normal sized people and getting off on it. It is very very irritating.

I imagine green mana acts like a world's oxygen level. Pump up the levels and you get dragonflies as large as eagles. It doesn't feed things (necessarily), but it makes big things possible; it helps growth along. You get as much or more growth, with less matter consumed.
Still, that doesn't explain why we don't see a jump in size or numbers at lower levels of the ecosystem. Maybe the trees all grow, and the rabbits all breed more quickly, but predation keeps pace so we don't see much effect.
The other possibility is that only certain animals have evolved to make effective use of mana. These are the animals that grow huge. But to become dependant on mana may mean limiting your population growth. Perhaps mana is easily monopolized. The right animal at the right time could snag it all and become all-powerful.
Perhaps creatures get their mana from eating other mana-rich creatures, so that accessing the flow of mana opens you up to a whole new foodchain of predators? That'd be cool.
Or maybe none of that is the case. Perhaps we should ask how long the megabeasts of most planes actually last. Maybe once the out of control growth starts the clock's already ticking. Some animals never stop growing, and at some point become unfeasibly large. Does that account for some of them?
I doubt we'll ever get confirmation on the issue.

They sustain themselves on rule of cool.

I imagine, in the case of Ravnican monstrosities of Simic origin, they originally ran on Plax, and that there weren't many experiments running around...at least not enough to constitute the need for an ecosystem for them. How they kept things like an Indrik fed......the Selesnya and the Golgari did make great strides in food production.