Etymology of Slang Sexual Terms

Pussy, Beaver, Poontang, Snatch, Dick, Johnson, etc...

We've all heard the terms, and we've all used the terms. Have you ever wondered how they became common references to vagina, penis, etc?

(As an aside, yes I know it's a Saturday night and I'm sitting here at this computer starting a silly thread, when I'd much rather be out getting some instead of talking about it. But alas, there is a temporary shortage of gentlemen named Benjamin in my life at the moment...)

So, let's have some fun with this thread. Post funny (or even stupid) comments, or post actual facts about the etymology of your favorite slang terms. It doesn't matter to me. To Begin:

"Pussy":
From the quick research I've done, the consensus from most etymologists seems to be that the origin of "pussy" in reference to a woman's genitalia is either the Low German word "puse", meaning "vulva", or the Norse word "puss", meaning "pocket" or "pouch".
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(Yeah, I thought it was going to have something to do with a cat, too.)