The Undertaker loves UFC, to the point where he actually started using MMA moves in the WWE ring. Remember his Hell's Gate? That's just a UFC gogoplata. Remember his Big Evil nickname? That's just a tribute to Jens Pulver's Lil' Evil nickname in UFC. Taker even started wearing MMA gloves in the WWE ring, such was his passion for the sport and his wanting to look like a legitimate tough guy. He admitted to Ariel Helwani (in the same interview where he challenged Brock Lesnar at UFC 121) that it would have been a sure bet he would've went into MMA if it had been as big in the nineties as it is now. His reason for not going over to the sport in the mid nineties was the money. He was earning a handsome sum in the WWF, while UFC fighters were earning pittances. Even today, lower card fighters only really earn enough money to cover their fight camp costs.