Snakes have 2 hemipenes aka 2 seperate penises, though they can only use 1 at a time which depends on the way the female is twisting when they do their funky spaghetti bowl mating.
While that's all I really know about snake penises, I do know a lot more about mammal penises if you care to listen!
Male cats (toms) have barbed penises! The barbs face backwards on the shaft (towards the body of the tom) because cats are promiscuous breeders (they breed with EVERYONE) the toms have developed the barbs as a method of ensuring that it is their seed that impregnates the female cat (queen) the barbs scrape the inside of the vagina and scrapes out any competitors seed! It also acts as a stimulant to the queen causing her to drop an egg!
Boars/pigs (and ducks funnily enough) have a corkscrew shaped penis tip/whole penis (the boars and pigs only have the corkscrew tip) the procine penis is shaped like this to fit in the corkscrew cervix of the female pig (sow) while for ducks the whole corkscrew unravels and ravels rapidly during mating like those pretty swirly ribbons people set up as garden decoration!
Female Hyenas (bitches. Yes that is the actual word for it) have a pseudo-penis which is basically just a super long clitoris!! Because of the funky shape, it makes forceful mating super difficult on the males meaning that its in their best interest for the females to be active and willing participants. This allows the females to be more in charge of choosing who to mate with, as well as them having a matriarchal social group! (Win for consent!) They also give birth through the super long tube which is very dangerous and often leads to complications.
Ram penises have little tails! At the tip of the penis there is a thin and delicate filiform that spins rapidly during ejaculation!
And while its not a fun fact about the penis itself, it is something I think about whenever the horse penis is brought up in conversation: often times horses are bred through artificial insemination, and the way they collect the seed from the stallions is to get them aroused by a mare and then stick their penis in what is essentially a horse sized fleshlight and let him have at it! There are people out there who's job is to guide a horse's erected penis into a giant fleshlight.
On the topic of horses, the penile sheath tends to get all sorts of gunk stuck in it so the owners have to clean it out by hand. And I do mean By Hand.
Enchidnas have a four headed penis! When aroused 2 of the heads will be functioning and this alternates every time. They also don't urinate using their penis and instead urinate through their cloaca (they are 1 of only 5 living mammal species that have cloaca!)
