(Mainly because Mr. Klaus is bored lol)
The outrageous iron clad man had been waiting for the day he would asked to bring people joy and presents! It was his dream in life to see the happy faces of people when they opened gifts that they wanted.
But that didn't happen. Why?
HE LOOKED TOO FUCKING SCARY!!
Everytime he would try to be nice to a kid they'd kick him in the balls and run screaming. It also didn't help that he usually turned said kids into popsicles afterward.
Then when he learned that Mr. Klaus had taken the position he wanted, and didn't even want it himself, Jak lost control! He vowed revenge against Mr. Klaus for taking his dream away and no prank would be too big to see it happen!