In Halo 3, this means to get 8 kills in a row within a 4 second timeframe for each kill.
Oh yeah Killpocalypse jabronis!
Actually you noob it means getting 9 kills within 4 seconds of each other
Blood Clot Lach: Yo i got a killpocalypse
Da Kid Pupple: Thing is dat u mad dough
Blood Clot Lach: Im nat dough
Da Kid Nighty: Were you at least playing ranked?
Godzilla6000: EYE MEAN im sure u is a nice guy
Da Kid Krautz: We can have a brewski
Blood Clot LAch: Nah i was playin griffball
All: NAHERRRRRRR YOU MANGO