Punchbag Bob is a test opponent in the Battledome that deals no damage. Being such a glutton for punishment, he's a generally well-liked character even though people still enjoy testing all their new weapons on him.
Oh, it's you... Let me have it!
OUCH!! Why don't you go pick on someone with weapons!!!
OUCH!!! I HATE BEING A PUNCHBAG!!
Well of course you won, I didn't fight back! Want to practice anymore?
Ok, buy some real weapons and we will try again!!!