Er, yeah, that's... kinda what I was saying before The darkeye monsters and their palette swaps cling to stuff with their smaller set of feelers. They had been upside down in earlier games because they were hanging from the ceiling (props to Dwaine for his site) but due to these recent monster titles having larger beasts and a general lack of ceilings the monster was put on the ground.
They're different from the ones that appear in V, though. Or some of them are, at least. I KNOW there was a topic going over these localization changes and how they were appropriate in instances like these...
I remember looking into this a bit back when videos of Terry's Wonderland were going around since one showed off a very electrically-inclined bird that looked nothing like zapbird. Can't say I remember which topic it's in now, but I do remember comparing the Kana and, unfortunately, the zapbird was given that appearance. (it's a size 2 reskin of the firebird / phoenix and snowbird / blizzardy monsters. Still cool, but I can't say it lives up to zapbird's original design. Kinda makes me think of how they've derp'd out the nardragon since Joker)
I wanna say I saw the giant worm / wiggly before, and I think it's a palette swap / reskin of wormonger. I guess the change in size is a little bizarre, but after playing the first Slime Mori Mori I can see a little why they'd make it so big (it certainly is GIANT now)
As for darkeye, I'm pretty sure it (or something very much like it) was brought back in Joker 2 (along with a red variant, I can't recall either of their recent names at the moment, though) but it was something I didn't realize for a while because they changed where they attach. With the 3D environments and giant monsters and everything, it's kinda tough having low ceilings in fights, so they're hooked onto the ground now and are 'upside-down' from their original appearance. One acts as the first boss in Joker 2, even.
Hopefully none of that's misinformation, but it's certainly close to what I remember at the moment.