It's racist slang for black people. Like how some other term of which I forgot but I should really know is racist slur for Cubans.
I mean nothing offensive by that.
And indeed, it's getting too far. So to get it back, I present this.
Low percents: Ness >>> Mario
Mid percents: Mario > Ness
High Percents: Mario > Ness
Really high: Ness > Mario.
percents as opponents percent. At low percents, Ness can do many things. Mario can spam fireballs and grabs. And mid percents, Ness' combos start to wear out [still got them though till a certain point], but that's where Mario shines with uair combos, and if he plays his cards right, can finish off the opponent with a usmash. At high percents [up to maybe 120%], Ness has little options, but Mario can no longer really combo as well. Time to edgeguard, but Mario is a bit better than that [Ness has dair, but Mario has way better recovery and fairs, nairs, and fireballs. Ness has WAY better grabs though, and unlike what Koro said, can jab to grab, but it helps Mario more]. Ness' utilt, or was that dair, leads to a bair to setup and edgeguard, but little more than that. At even higher percents though, many of Ness' moves become KO moves, like uair [which has broken priority by the way]. Mario is still mostly the same, just that bthrow will likely kill.