A banana slug can be 6-8 inches and their erect penis can be just as long. Also, their penises emerge from their heads. After sex, banana slugs eat each others penises.
17
Condoms were originally made of animal intestines or linen.
347
Cymothoa exigua is a type of parasite that enters through fish's gills, eats their tongue, and then replaces it.
6
In Brazil, there's a species of cockroach that eats eyelashes, usually those of young children while they are asleep.
151