Ofter a person in an online internet game who kills their own team mates for the "lolz". In other terms they may do so because they find their team mate inadequate at gaming, in which case they will team kill nubbies.
"Why are you killing your whole team?"
"Just for the lolz."
"WOW you're such a TEAM KILLER"
"I Team Kill Nubs"
"Dude we're only on easy."
"Bounce back to nub land.:
"Don'te be such a TEAM KILLER come on!"