I think you are thinking of MANGLORs... although I could be mistaken.
Thanks for the tip. The thing I'm talking about is very, very close to the same thing as the Manglors. I looked up a Manglor guide, but didn't see the two figures I remember (the dark green man and dark red bird-creature), so I guess it's not the same thing.
My older brother says he remembers the dark green man being a Swamp Thing figure. Was there any kind of Swamp Thing figure that was basically just like the Manglors?
p.s. I stumbled across the "Rocks & Bugs & Things" toys when looking up Manglors guides .. we definitely had a ton of those in the bottom of our (football-shaped) toy box