If you control two or more other lands, Hydra's Nest enters the battlefield tapped. T: Add G. XG: Hydra's Nest becomes an X/X green Hydra creature until end of turn. It’s still a land. X can't be 0.
The Green member of the manland cycle's ability is variable size, which may or may not be to its detriment. At the very least, you can dump your Treasures on it. Kinda sucks this ditched the negative space treatment.
At least Green received a thematic, good one. Then again, of course it would.
Sad that blue had literally nothing to do with krakens or sea monsters, despite the amazing art, and instead gave us Giants, which can be in any color, and already are as a cycle, instead of having cool sea creature synergy, like this one has with Hydras, which is far more thematic and popular. But I suppose no matter how much it is requested, we can't have nice things.
That said, I'll actually play this one in my sea monster deck, since I love unique lands. What a disappointment the blue one turned out to be, truly.