Quillgin

Quillgin is the evil elf, appearing in "The Christmas Special". He has a gun and grenades.

He spent his life working on a present that would give children whatever they most wanted. But unbeknownst to Santa Claus, he used dark magic as a key component. In testing the box, people turned evil, so Santa ordered his elves to destroy Quillgin's life's work. Quillgin came back for revenge on Christmas Eve, but he and the gift were destroyed in the lava pit at East Pines.