Zekke
Green Slime
Not sure if this is a bug or intentional, but when a monkey is frozen, and you hit him until he goes into the panic state that they do when their health is low, he becomes untouchable in the ice until he melts. Not game-breaking or anything, just kind of annoying to wait until they thaw each time before you can kill them.
Pretty bad photo, sorry, but the monkey in the panicked state can't be hit by the fire or anything else until he thaws.