Used as an insult to
demonstrate authority, hence the "daddy" part. Most likely performed by the giving end
after the recieving end is pwned/owned. Also used by Superfly, one of Joe Cartoon's characters.
Billy: Oh yeah! I just scored 15 3 pointers on your punk ass!
John: Dammit, man..
Billy: Who's your daddy?!
Superfly: Hey man, what's up?
Santa: What's up? Heh heh. What's up?
Superfly:
You know who your daddy is? It's me, yeah!
I'm your daddy! Do you know how come
I'm your daddy? 'Cuz I did this to your momma! Yeah, YOUR momma! Call me Superfly! Your momma!