Proportionally, snails have the largest genetalia of all living creatures (or so my science professor told me) and they are hermaphodites so the can reproduce on their own. :\ boom. Snail knowledge, yo.
Actually it's the sea creature (I cant remember the name but can remember the video it's on YouTube just search for it you should find it.) as It is always stuck in place they have to reproduce somehow you know, it would be the equivalent of a human male having a 30 meter genetalia so you can picture how large they are on the tiny creatures but you have the hermaphrodites thing right as my giant African land snails reproduced when I was younger we had been told they were all female stupid breeder.