The Undertaker probably has more gimmick matches associated with him than anyone else. From Hell in a Cell to Buried Alive, Last Ride, there are a bunch. However, the one he considers to be so pivotal to his character was the Casket Match.
During his appearance on WWE’s The Bump, The Undertaker went into detail about the stipulation. He said the matches really caught people off guard in the early 1990s. Here is the quote, courtesy of Fightful:
“I think those early casket matches were so pivotal to the character because they were so, you’re talking about the early 1990s and nothing like that was being done. Just the concept of putting your opponent in a casket and everybody has their ideas of caskets and some are very squeamish about them. Other people aren’t bothered by them, but the fact that you’re taking your opponent and locking them up in a casket kind of reiterated that the Undertaker character is on a whole other level of what wins and losses looked like.
I think those casket matches and the body bag matches were crucial to the development of the character and setting it apart from every other character out there because nobody else was doing it. There were cage matches. There were No DQ matches, but to lock your opponent in a casket, it really caught people off guard considering the time period in which we did it,”
The first Casket Match can be traced back as early as 1992 at a WWF live event in New York. Since then it has been a signature match of The Undertaker with the last one coming in 2018 against Rusev.