Other than WrestleMania X and WrestleMania XV!, he has been present at each WrestleMania since WrestleMania VII.
During this time, he has had the greatest run of matches in the history of the pay-per-view, with him getting 21 straight wins at WrestleMania before he suffered his first defeat at the hands of The Beast Brock Lesnar at WrestleMania 30.
The Undertaker would return at each of the following WrestleMania to defeat Bray Wyatt, John Cena, and Shane McMahon. He would only lose against Roman Reigns.
However, this year was the first time since WrestleMania XVI, that the Undertaker was not present at WrestleMania. Given the length of the pay-per-view, he was not missed.
Here are 4 reasons why the Undertaker was not at WrestleMania 35.
#4 The pay-per-view was too long
Let's talk about the elephant in the room. WrestleMania 35 was amazing, but FAR too long.
As a result, the matches that came towards the end of the show suffered from crowd exhaustion. They were not able to deliver all that they were capable of because of the tepid reaction that they were getting from the exhausted WWE Universe. The show was 7 hours and 30 minutes long.
At some point, WWE has to bite the bullet, and either reduce the length of the pay-per-view or split it up in two. This way, the matches would be distributed over a longer period of time, allowing them more freedom to work.
On top of everything that happened, if the Undertaker was to make a meaningless appearance on the show, it would be a waste of WWE resources as well as time which could be given to one of the matches (Looking at you Rey Mysterio vs Samoa Joe).