There are so many different kinds of penises. I have been thinking about a few penises. They are quite amazing.
The Tasmanian Echidna has a penis with four heads.
‘Echidna is the most primitive mammals still living, and displaying many archaic traits inherited from mammals’ reptile ancestor. Male echidnas ejaculate with just two heads (half of the penis) at a time. This resembles very much the way lizards and snakes ejaculate: they have a double penis (hemipenis), but only one of the two penises is used during the copulation, while the other will effectuate the next copulation/ejaculation. Marsupials (another primitive group of mammals) are now in this matter something between monotremes and placental (evolved) mammals: they do not use half of the penis for mating, but still have a double headed penis, while the echidnas have a reptilian joined hemipenis, with each part of the penis in a marsupial-like fashion.’
Leopard slug penis.
‘Two leopard slugs in the condition to mate, crawl one after the other, the back one almost touching the front one. Both crawl towards an overhanging part of a wall or a tree branch, from where they rope down on a slime thread about 16 inches long.
Hanging freely in the air they then mate by extending their penises and entwining them. Doing so, they make a characteristic flower like structure below them, where the spermatophores are exchanged. Slugs are hermaphrodites, they are males as well as females.’
‘A male cat’s penis has a band of about 120–150 backwards-pointing penile spines. Upon withdrawal of the penis, the spines rake the walls of the female’s vagina, which is a trigger for ovulation. Female cat utters a loud yowl as the male pulls out of her.’
‘The octopus penis is detachable. The male introduces penis into the gills’ cavity where it deposes the spermatophores. During the mating, the male loses its penis.’
Female ‘bed bugs have fully functioning sexual organs but male bed bugs mate by stabbing female bed bugs in the belly using their sword-like penis and ejaculating directly into the female blood stream. It’s called traumatic copulation.’
Female hyena‘s clitoris gets erected and it looks exactly like a penis.