Although real licensed music was not unheard of, Kid Rock and Limp Bizkit performed a couple of his themes, paving the way for bigger bands and artists (Disturbed, Motorhead).
Not considering his Bikertaker days, his theme is usually a variation on Chopin's Funeral March.
Fan Nickname: "The Bikertaker" for his "American Badass" gimmick, chiefly because of his habit of riding a motorcycle down to the ring during this period.
The "Logofixion" for when he crucified Steve Austin to his Tx symbol (and again years later to Orlando Jordan).
Funny Aneurysm Moment: Play 'Taker's story modes in the Smackdown vs. Raw series and you'll find several uncomfortable examples, so much so that fans have talked about "Undertaker's Curse":
Smackdown vs. Raw 2006 had a storyline finish with The Undertaker chokeslamming Eddie Guerrero into a casket. Two days after the game's release, Eddie was found dead in a hotel room.
One of the most uncomfortable examples of this ever is in SVR 2007, where 'Taker fueds with another wrestler while playing up the supernatural part of his character and tells the other guy his own persistence will be the end of him, and his family and friends will have only him to blame for the bloodshed. That other guy was, of course, Chris Benoit.
Jeff Hardy had a storyline with The Undertaker in the 2008 edition; around the time the game came out, his house burned down and he lost everything (including his dog).
Any time he's wrestled someone who later died probably counts, given that his gimmick is centered around death. There was at least one time where he was in a fatal four-way with the British Bulldog, Owen Hart and Yokozuna (for those who don't know, out of these four, Undertaker is the only one still alive). Rest in peace, indeed.
Holy Shit Quotient / I Have the High Ground: Just try to keep your jaw off the ground when he suicide-planchas over the top rope. Keep in mind this is a 6-foot-10, 300-pound man running full speed toward the ropes, and diving over them headfirst. He pulls one out every Wrestlemania.
And still doing it well into his 40s.
Internet Backdraft: Go on a forum and state that you feel The Streak should end. Go ahead, do it. Now go ahead and roast the marshmallows on the flames.
In fact, say anything bad about 'Taker in general. Just about the only thing most people will give you are that his best days are behind him, and even then it better be said with a respectful tone or else they will jump down your throat.
Just Here for Godzilla: "The Streak" is getting close to this level, as a few smarks nowadays say "The rest of the card looks like its gonna suck. I'm just here for Undertaker anyways." Now granted, more often then not they usually end up eating their words when it comes to the rest of the card, but it still technically applies.
Especially with the last few WrestleManias, the Undertaker matches have outshined all the others.
Memetic Badass: Both in and out of Kayfabe, to the point where simply just looking him in the eye without flinching gives you uberBadass points.
Memetic Mutation: Theodore Long: "NOW HOLD ON JUST A SECOND, PLAYAH! Tonight, you're gonna go one on one with...DA UNDATAKAH!!"
Special mention goes to a feature magazine that had Taker in a coffin. Sellers were fairly freaked by the cover and were wary of selling the publication.
So Bad It's Good: Many of Undertaker's promos, and arguably, Undertaker's gimmick itself. The fact that The Undertaker takes the gimmick so seriously helps.
Narm Charm: Seriously, it can not be exaggerated just how silly The Undertaker's gimmick is. And it works, just because it's played so straight.
Special Effects Failure: Not too often, given that you can only expect so much out of WWE effects-wise anyway. However, one glaring example was at a recent Wrestlemania when they tried to make it look like Undertaker was 'levitating' to the ring. A camera angle from above revealed he was standing on a moving board, the fog in his entrance wasn't thick enough to hide it.
Then there was the botched pyrotechnics at the Elimination Chamber PPV. Undertaker suffered 1st and 2nd degree burns when the fire in his entrance lit his Badass Longcoat on fire.
Which will probably lead to a number of flame wars over this being part of his gimmick.
The wig he wore upon his return in 2012 was a study in hilarity.
The Wrestlemania XXVII match as well. Kayfabe or not, it was just depressing seeing The Undertaker barely able to get out of the ring, even if he did win the match.
Kayfabe would've involved druids and chanting and blue lighting and fog. This was not kayfabe.
Took The Bad Gimmick Seriously: Though the gimmick would sound silly at first glance, it was perhaps Undertaker's sheer devotion to it that makes it work so well.
Uncanny Valley: Undertaker makes use of this trope as part of the psychological warfare he plays on his opponents. Rolling his eyes back, sitting up right after taking a huge bump and appearing to impervious to pain are all things which make him appear inhuman.
Visual Effects of Awesome: Awesome as far as anything in professional wrestling can be. His entrance itself, the occasions where he shoots lightning at people, his symbols that spontaneously combust, among other things. It doesn't matter if it's fake, his kayfabe is still awesome.