>>5750003To start, I'll just go with the two favorites, Snap Up Swamp Thing and Snare Arm Swamp Thing.
The better of the two is probably Snap Up, as his gimmick caused him to have the most articulation of the group, though it's all string connections. Basically, pull him apart and flop him on the table so he looks like just any old pile of swamp dross, then press the button and he springs together into one piece again, ready to take up his rather crappy weapon of a hollow log with finger-flick vine 'snare'.
Snare Arm is the runner up because he's got the good ole bionic commando arm gimmick, where you can stretch it out and then real back whatever you latch his grubby hand on by squeezing his legs together. He also comes with a little trap that's a pretty nicely detailed, basic design, basically flip the upper 'jaw' up and there's a leafy 'tongue' that brings the 'jaw' down again should you press on it. No spring in it though, so it's a little weak, just looks good.