Most people nowadays have at least heard of vore, but how does endosomatophilia (sexual pleasure from being swallowed whole and subsequently sitting in your partner's stomach without being digested) strike you?
If you'd prefer safe for work stuff, there are plenty of common fictional animal species that people commonly use for their fursonas, like the protogen (cyborgs with their iconic black visors, with a ridiculous amount of lore behind them) and the avali (a bipedal birdlike creature with a snout and four ears). There's also digitigrade (an adjective describing animals or furry OCs that walk on their toes, like wolves and horses do) vs. plantigrade (walking on the soles of the feet like a human does) although we sort of borrowed those terms from the biologists.
At the end of the film they discover that children laughing generates way more power than screaming does, so the monsters start doing comedy routines instead of trying to be scary
