Kilter is an immortal and a former servant of the Great Ak. He was assigned to assist Santa Claus and always accompanies him on his annual Christmas journey.

Kilter is known as the "silent and swift", and has been referred to as a pixie. He is a quiet fellow who seldom speaks, but he can pass through walls and closed doors. It is his duty just before Christmas to gather up the notes and letters from children to Santa Claus. (The Life and Adventures of Santa Claus, "A Kidnapped Santa Claus")

In adaptations

In Alex Robinson's 2008 adaptation of A Kidnapped Santa Claus, Kilter is a recently hired stablepixie in charge of taking care of Santa's reindeer. Wisk has a crush on him and she ends up joining the toy run partly for the opportunity to spend time with him in addition to her suspicions of the strange visitors in the days before Christmas.