From Chewiki: 1% Funny, 99% Hot Gas
Robotnikclaus is the arch-rival/alternate form of Dr. Robotnik. Unlike Robotnik, who has a PINGAS, Robotnikclaus has a PINESS, which, according to him, is much more enjoyable, especially when it's based off of the misery of others.
What started out as Robotnik dressed as Santa Claus became serious when he was zapped by a beam of Anti-Uctions fired by Mama Luigi. The radiation soaked into him and his attire, and in a few days a clone seemingly morphed out of Robotnik's skin, with its own copy of the Santa Claus clothing coming out with it. This clone, made of Anti-Uctions, became a rival to Robotnik, using its PINESS to counter Robotnik's PINGAS.
Robotnikclaus lives at the North Pole, and has presents delivered to him every Christmas. He has one minion, a stupid looking generic robot, and he plots the demise of his counterpart. Because he was created by Mama Luigi, Robotnikclaus is loyal to him, as one of his upper ranked minions, using his PINESS to enhance the AIDS.
In spite of his rivalry with Robotnik, they both recorded a hit single together titled "Piness Piness Pingas Pingas". Stimpy J. Cat likes to play it constantly, much to his friend Ren Hoek's displeasure.
Robotnikclaus can be seen in the AoStH episode "Sonic's Christmas Blast." Some say that the PINESS in this episode is a reason the show got cancelled.