In the sport of professional wrestling the athletes are known for their ability to talk a big game and run their mouth to their opponents.
As we know, The Undertaker was a creature of few words and did his talking in the ring and not on the mic. When he was tired of hearing his opponent talk, he would simply take his soul by way of a devastating tombstone. As the casket door closes and his opponents body is lowered in the ground, what you don't hear is talking because Dead Men Don't Talk!