A W.O.W body is one that has become fat, ugly and out of shape due to hours of playing World of Warcraft.
Dave: Dude, I've got no idea what to do on this homework!
Joanna: Just ask Neville the Nerd for help.
Dave: Who the heck is Neville the Nerd?
Joanna: Oh, you know that smarty-pants kid with the W.O.W body.
Dave: The one with the love handles and man boobs?
Joanna: That's the one!
Dave: Oh yeah! That dweebster knows everything!