Female anglerfish are enormous compared to their male companions. When a male is ready to mate, he fuses to his sweetie and spends the rest of his days as a living sperm sac.
Male Birds of Paradise have evolved stunning feather displays to impress the choosy females.
Barnacles are cemented to their home rock, so instead of going out to find a mate, the males stretch their very long penises into a neighboring female’s shell.
Who needs men?
All salamanders in the genus Ambystoma reproduce by cloning.