A person who is such a chump that "Chump" would be warranted as part of their last name. Alternatively, a chump who is smaller, the younger sibling of, or acts like a chump to less of a degree than a real chump.
Chump: Hey guys!
Everyone: Whatup chumpsky?
Yannick: Yaow Yaow!
NetStryke: shut the fuck up chumpsky.
Homie: Yo what's poppin chump?
Chump: Hey dog..
Homie: Why you so down? Oh I know why, your girl's out bangin dat dude again huh?
Chump: Fuck you man!
Homie: Haha, man I thought yo last name was Chumpsky the way you're gettin chumped!