If you have the endurance to lug a huge chain around your neck and you can do a good wolf howl, this might be a good option for you. Just stay away from anyone dressed like Chuck Liddell.
If you don't have the typical fighter body but don't want to be left out of the festivities, "Big Country" has you covered. Don a beard and signature Roy Nelson mullet. Some fight shorts and gloves will add to the costume. Keep it real by losing your shirt and rubbing your belly periodically.
You'll need: A dreadlock wig pulled back into a ponytail, black slacks and short sleeve collared shirt, latex gloves. Address everyone using the two-finger Herb Dean Salute. Tell people at the party to obey your instructions and defend themselves at all times. If people are standing around tell them "C'mon, let's work!" If they're sitting tell them: "You have to work or I'm gonna stand you up!"
Get a 209/Gracie Jiu Jitsu/Dethrone shirt, scrunch your face up into a mean mug and write 209 with a marker everywhere. If anyone asks your opinion on the party or anything else be sure to respond with, “That’s whatever, man. I’m just here to fight."
If you're comfortable walking around in a bikini, make yourself some eight-sided cards to hold up and practice blowing kisses at any cameras at the party. We prefer this costume on women, but it's a free country.
Get a shiny suit, some large index cards and announce people as they arrive. "This man is a Dentist, working out of Coconut Creek, Florida! James "Smiles" JOHNNNNNNSSSSOOON!!"
For added effect, turn only in dramatic 180-degree increments.
Alex Caceres aka Bruce Leeroy
Do you know what a good deal you can get on that Bruce Lee/Kill Bill outfit in 2010!? Or borrow a friend's from a few years back. Slap on an afro wig (power fist pick optional), grab a goblet wear a smug grin and you're this season's love-to-hate-him star.
Brown Pride Poncho Dude
Got a sombrero and a blanket? Throw 'brown pride' up on that bad boy and you're the epically underpublicized Brown Pride Poncho Dude, as seen in this montage of fans at UFC 121.
Joe Rogan & Mike Goldberg (team costume)
Work out who’s going to be Joe and who’s going to be Goldie. Then get two fake microphones and attach the UFC logo to them. Wear some MMA-branded button-up shirts and walk around commentating at the party:
Mike: Hello UFC fans, I'm Mike Goldberg here with my partner, as always, Joe Rogan. Joe, what do you think of this Halloween party?
Joe: This is a phenomenal party, Mike. We've got a guy dressed as Freddy Krueger and those razor hands are going to give him a definitive reach advantage.
Mike: Approaching the snack table, is the sexy penguin. This party is sponsored by Bud Light! When your party is really heating up, cool down with an ice cold Bud Light! Drink Responsibly.
If someone does drink too much be sure to yell, "He's rocked!" Also try to stay until the end of the party so "Mike" can yell, "It is ALL OVER!"