Mating barnacles from Casey Dunn on Vimeo.
"Hung like a gorilla" is not a compliment and hung like a duck is, but if you claim to be hung like a barnacle, you are just a damn liar.
Barnacles are stuck to rocks, which could make it tricky to get close enough to a partner to mate. They have solved this problem by evolving the longest penis relative to their body size of any animal. In this video the penises of several barnacles are probing the neighborhood for mates. The penis is re-grown each mating season..