The smaller symbiote crawler enemy, with an anguished "expression" on its face as it's held by another character not included in the graphic.
The larger symbiote brawler enemy, doing a bite attack where its neck is twisted with powerful torsion a few rotations and its teeth are exaggerated. It was just the start of a basic combo string, but I wanted to give the enemy something very distinct for this pose as it is not often that you get to play with what is effectively a character made of rubber.
The brawler enemy again, this time on all fours with a forward crouching roar type pose. This was a projectile spitting animation, which I took an animalistic approach to as I wanted to emphasize the inhuman nature of these guys a lot.
The smaller crawler enemy in a pose where, despite the bottom half of its "jaw" being the right way around, the top half of its head... shape... has been knocked roughly 180 degrees around. While these things don't exactly have faces, I had a lot of fun giving them exaggerated and rubbery poses like this one as they weren't bound by the kind of physical constraints other characters were.
One of my fondest memories working on Marvel: Cosmic Invasion was getting to design the key poses for the symbiote enemies. The game has been out a while so I figure I could share some of my favorites, sprites pulled from Spriter's Resource