Rituals and superstitions are actually a pretty common thing in sports and can be seen across the board among athletes of all levels even including some major stars.
You've got to think in a sport like MMA a lot of fighters are going to have their fair share of rituals and superstitions with it being such a high stakes game with so much on the line. In the following video we see some of the weirdest and craziest rituals of MMA combatants and some are very bizarre.
It seems a common one among a few different fighters like Josh Thomson and old school vet Matt 'The Law' Lindland is not showering leading up to a fight for some strange reason. They each had their own different reasons for it though apparently. In Thomson's case it was more of a superstition than anything whereas in Lindland's case it was to make himself smell so bad it threw his opponents off during the fight.
Rampage even hilariously commented on it after their fight (which Rampage won) during the post-fight interview saying fighting Lindland was like fighting a skunk and even advised 'The Law' to take a shower sometime.
One of the strangest rituals involves all time great Jon Jones who revealed on Joe Rogan's podcast that he would get black out drunk a week before the fight. This was to take the pressure off and give himself an excuse if he lost so it wasn't his fault, it was the fact that he drank a week before.
Probably the most crazy ritual/superstition ever is Benson Henderson's obsession with tooth picks. He likes to have them in his mouth DURING a fight which is absolutely crazy. That can very well result in an injury after taking a good shot to the chops or even if you accidentally swallow it, it could cause some serious problems. Hopefully the referee checks his mouth a little more carefully before his next fight.