This was a creature I made a while back that's sort of like a slime monster, but holds their shape a little better. It generally has no mouth, but when it chooses to bellow or scream, a rip and crackling sound occurs beforehand as it basically creates a mouth for itself. The mouth always looks like dripping fragments until it closes, seamlessly disappearing again as the creature goes quiet.

I love this goopy critter and have named them "Whisper."