Parasitic Males

At work today, I was reading an article in wiki about sexual dimorphism (don't ask), and this particular bit had me in stitches:

"Some species of anglerfish also display extreme sexual dimorphism. Females are typical anglerfish, while males are tiny rudimentary creatures with no digestive systems. The males must find a female and fuse with her – he then lives parasitically, becoming little more than a sperm-producing body."

I don't know why, but that passage reminded me of a certain species of mammals too.