I think they are still called deku babas too! Thanks for the name, I don't really know what they are called, specially in English. I just wanted to get the idea across.
I think a hard one would the creatures that seem made of lava that falls from the roof in some parts of the Goron mines of Twilight Princess. I don't know if they stay there like bats, or are just up there because they are 'sticky' like snails. Heheh.
They are like fire slugs, like the ones from OoT, only they stick on the ceiling, and the creatures in the original Zelda "evolved" from creatures in the real world, and all the other games' creatures are evolved versions of the originals. It just shows the evolution process in Zelda.
One I wouldn't understand: The miniboss in the Fire Temple from OoT. I can't remember it's name, but it's head would explode if you beat it.