I'll out do that vurt, consider the australian marsupial mouse or antikinus, when males reach sexual maturity their balls swell to 2/3 their body weight and they feel the desire to fuck to the exclusion of all else. After a 3-6 month fucking frenzy they remember that they forgot to eat, sleep etc and promptly die, don't believe me ask a zoologist or one of those freaks who gets off on watching animals fuck (why are you looking at me, my friend told me i swear!). Sorry i don't know about their pee-pees but considering i've just talked about balls in this phallocentric thread i don't feel i have to qualify that with an answer!
P.S. Humans have the biggest cocks of all primates