He was frequently in casket matches. 2 of the most famous ones came against the late great Yokozuna. The first one was at Royal Rumble 1994. Undertaker had the match won (WWF Title was on the line) when he was assaulted by at least 7 guys. The rematch came at that year's Survivor Series. Karate expert Chuck Norris was at ringside to make sure there was no interference(Undertaker won).