The Undertaker/Heartwarming

Mark Callaway and Glenn Jacobs appearing on America's Most Wanted to appeal for viewers to turn in someone who beat one of their fans. This was during the Bikertaker days rather than his long running death zombie gimmick.
Taker's farewell to Ric Flair.
After Batista did his heel turn in 2009, he and Rey Mysterio, Jr. got in a feud. After a particularly brutal street fight, Batista ended up being the victor. But Batista wasn't done. After the match, Batista went out of the ring and got a steel chair and opened it up, leaving enough space for Rey Mysterio's knee. He climbed up the turnbuckle, and was about to jump on Rey's bad knee. But The Undertaker wasn't about to let that happen... *GONG* Cue the lights going out, they come back on, apparently Undertaker saved Mysterio and gave Batista an ass beating to remember. The fact that Undertaker went out of his way to save little Rey is definitely a CMOH.
The Undertaker teams up with Wish With Wings to grant a wish for a little girl with cancer. D'awwwwww...
During Shawn Michaels' heart-wrenching retirement speech, The Undertaker's music hit. Taker comes out, as if to do his signature hat-removal, and tips his hat in respect before returning to the back.
There was a DVD during his biker days which delved a lot into the real life Mark Callaway...sorry. At the end he is in the locker room talking to the other wrestlers, not sure if it was an angle or if this was real life, but he says these words.

"There's no shame in going out there and getting your ass kicked. There's no honor in not fighting at all."

- Words to live by.
  - That might have been from the InVasion angle, when Undertaker gave a Rousing Speech to the WWF wrestlers before they squared off with the WCW/ECW wrestlers.
Undertaker getting a puppy courtesy of The Big Show. The crowd's reaction says it all.
Wrestlemania XXVIII: Undertaker with the help of Shawn Michaels hoists Triple H on to his feet and carry him up the ramp and where they later hug.