I don't love the frog. It feels like it might as well not have a Q ability since it bounces itself at instant speed anyway. It basically boils down to 5 mana make a 3/3 with buyback, which doesn't seem that fun. They even have reach so you can't beat it in limited.

Lotus Dryad is flashy but has to actually attack to be useful which I think is cool tension.

This is a tough one. I feel like Tek's card could be cleaned up a bit. Maybe drop the "without dying", maybe a keyword somewhere?
Cato's card is nice and simple, but might be too easy to abuse. The abuse case isn't too extreme, but could be trivially easy in some environments.

this is sorta where I'm at. especially with haste, it just kinda does its own thing, with stapled on for the criteria.

the dryad is spicy, but it does feel like the cost is intrinsic to its design. brushstrider says the body's ok, and while the mana's very powerful, the 1 toughness makes it very hard to use as traditional ramp without some other way to tap it. my one note is that they never printed a mana-positive card (or even a mana-neutral one, for that matter) and I think that on purpose. it's not that hard to find a free tap on an activated ability. you were clearly thinking about this, with the once-per-turn clause (which I definitely noticed right away and didn't write up a whole list of ways to break the version of this without it) but still, risky.

I wanted to wait for voting to finish, but it's looking pretty one-sided so far.

Lotus Dryad is really rad.

As a reminder, the poll is in its final hours!