Professor Monkey-for-a-Head releases some mutant eye-things
Mutant eye-things are one of the recurring types of enemy in Level 5 of the original Earthworm Jim video game.
They are failed experiments of Professor Monkey-for-a-Head, and the Professor unleashes the mutants upon Earthworm Jim in repeated efforts to reclaim the Super Suit which the Professor designed, and which Jim is wearing.
They simply resemble eye-balls which float by flapping two fleshy wings. Although easily dispatched with Jim's Plasma Blaster, they hunt Jim in groups, since the Professor releases groups of them from their containment units at the same time.
They can be especially troublesome in tight places, or when Jim is separated from his Suit, since they can travel through most solid objects.