The Undertaker, real name Mark Calaway, says he became a millionaire at age 27 and once banked just shy of $15 million in a single year. He shared the figures on the School of Hard Knocks, the interview series that asks wealthy guests how they built their fortunes. The Deadman did not name the year, but he turned 27 in 1992, less than two years after his WWE debut at Survivor Series in 1990.