Ever see a guy doing weird stuff on a wifi Brawl? Well he/she might be a fun fighter!
Fun fighters take the phrase "it's not if you win or lose, it's if you have fun" to Brawl. We (yes, I am one too) like to play around in ways that weren't intended in Brawl.
A fun fighter will do many things, including but not limited to; taunt spamming, crouching repeatedly, shield breaking, grabbing without throwing, move spamming (when no one is near them,) and self destructing repeatedly.
A fun fighter comes in two flavors. Type A will run away from combat to do his or her own thing. I am a Type A FYI. Type B will fight back if you fight him or her. If Type B's are in the same Brawl, they might gang up on a player that just wants to fight.
If you spot a fun fighter, just leave them alone. Chances are, they're a Type B with insane skills.