6) Barnacle - Despite spending it's entire lifetime bathed in frigid seawater, the barnacle doesn't suffer from shrinkage. On the contrary, the Dirk Diggler of the animal kingdom has a penis up to 50 times it's body length - making it the world's largest penis, relative to size. The reason size DOES matter? They're immobile and need the length to reach their mates.
5) Kangaroo - We've talked about interesting penis shapes before with the corkscrew penis of certain ducks. Pigs also have a corkscrew penis, but why go for a single freakshow when you can double your pleasure instead? Like many marsupials, the kangaroo has a bifurcated (or forked) penis, and the scrotum and testes are in the front. This matches the dual vaginas/uteri of female marsupials. Stranger still, the echidna penis (pictured) has 4 heads!
4) Dolphins - The dolphin, like some other cetaceans, has a retractable penis that is also prehensile, meaning it can grab, hold and wrap around an object (think monkey tail). Imagine the benefits of such an appendage! This guy did. But what's even more disturbing, is this joke faq about how to have sex with a dolphin. At least I hope it's a joke.
3) Argonaut - This specialized octopus can use its penis without having physical contact with a female. Like many cephalopods, the penis is a special tentacle called the hectocotylus. In the case of the argonaut it detaches and swims to its mate, embedding in the female and impregnating her.
2) Bee - Like any man, the male honeybee climaxes with an explosion. Unlike men, the male bee genitals literally explode and snap off inside the queen. Afterwards, the males do what any of us would if our testes exploded and our penis snapped off - they wander off to the corner and die. A similar phenomenon has also been observed in certain spiders. The evolutionary rationale is that the detached genitals act as a plug preventing other males from mating with the queen
1) Bedbug - The bedbug doesn't mess around with foreplay. In fact it doesn't even mess around with female genitals. Instead, the male uses its dagger-like johnson to pierce the body of the female and inseminate her. The bedbug isn't the only species with such a violent mating process. Hermaphroditic flatworms duel with their penises with the loser being pierced and becoming pregnant. I see your Schwartz is as big as mine!