Bogleech Halloween Classics:
These hollow, rubber monster heads actually came in four styles; skeleton, mummy, vampire and werewolf. The latter two featured "tongues" that would unfurl when squeezed, but their undead corpse pals put the "tongue" in an eye socket, as you can see here. My best guess is that this represents a "worm" writhing in and out of their rotten heads, which is awesome.
I nabbed both of the worm-eye heads when I encountered these, all the way back in 2002. Besides their morbid action feature, their designs are full of character and gross, gooey fun. The skull oozes blood and includes patches of exposed brain, while the mummy kind of looks like Rodney Dangerfield oozing with sludgy green pus, instead of the more purpleish secretions Rodney was known for.
Sadly, after ten years of alternate storage and display, these bozos aren't the pristine noggins they once were. They're stained a bit pink in places, following prolonged contact with other Halloween toys, and their eye-worms have very slowly disintegrated.