Santa Claus

Santa Claus, also known as Father Christmas or Saint Nicholas, is a jolly man who is the spirit of Christmas. He usually resembles a rotund human male in a red coat with white trim. He has a big, bushy white beard.

He delivers presents to children on Christmas Eve, flying through the sky on a sleigh pulled by reindeer. He is aided by a workshop full of elves.

Adventures of Sonic the Hedgehog
Santa Claus has appeared in the Adventures of Sonic the Hedgehog special, Sonic Christmas Blast as a major character. He was kidnapped by Dr. Robotnik, who usurped him as "Robotniklaus". Robotnik planned to steal Christmas and rule the world. Santa apparently announced his retirement, but in truth he had been replaced by Metal Claus, a dim-witted robot who was only programmed to say things revolving around Christmas.

Robotnik held Santa captive in an ice cave in the North Pole. Sonic rescued him but it still seemed hopeless, even by his abilities, to save Christmas. However Santa recognized the Ring of Ultimate Velocity on Sonic's finger and, with Sonic's help, was able to save Christmas.

Impressed by Sonic's abilities to deliver all the presents in the world in a matter of minutes he passed his signature red cap to Sonic, trusting him to continue delivering presents on Christmas Day. While Santa himself, would just plan out Christmas.

Sonic the Comic
A slightly different version of the character, primarily known as Father Christmas instead of Santa Claus, made several appearances in the British series Sonic the Comic. This Father Christmas possesses incredible magical abilities, the limits of which are unknown, which include the ability to appear and disappear at will and the ability to predict the future. He is also invisible to robots.

Father Christmas first appeared to Doctor Ivo Robotnik while he was dictator of Mobius, offering him a chance to do a good deed (although Robotnik refused) and predicting that Robotnik's empire would soon fall if Robotnik did not change his ways. Father Christmas later appeared to apprehend a villainous elf named Vile Peter, who had been kidnapping children from the Emerald Hill Zone.

Sonic X (comics)
In Archie Sonic X Issue 15, Sonic has a hard time believing that Santa is real. Sonic goes so far as to run to the North Pole and look for Santa's workshop. Later on, Dr. Eggman impersonates Santa, saying he will only deliver presents if the world delivers Sonic to him. Sonic is rescued by Chuck who claims to have the real Santa with him. Eggman is scared off by Santa, but it turns out it was actually Ella in a Santa suit. Now Sonic and Chris both doubt that Santa exists. Christmas morning Chris declares that Santa is real and Sonic (after getting a pair of Rings as a gift from Santa) agrees that it is good to believe in things.

Sonic the Screen Saver
In this Sonic software package, Santa can be spotted in the background of some of the screen saver images.

Fighters Megamix
Bark the Polarbear makes a playable cameo in this fighting crossover game. Bark's alternate costume is a Santa suit.

Sonic Adventure/Sonic Channel
SEGA has produced a lot of 2D Sonic artwork of the hero wearing a loose fitting Santa suit. This artwork first started as a bonus on the Sonic Adventure disc, then SEGA continued to produce new Santa Sonic art on their official Japanese website, Sonic Channel, almost every year. Some of this artwork can be unlocked in the museum of Sonic Gems Collection.

Sonic Rivals 2
In Sonic Rivals 2, one of Silver the Hedgehog's alternate suits in the game is titled "Christmas" and has a red, green, and white color scheme.

Mario & Sonic at the Olympic Winter Games
Santa Claus makes a cameo appearance in Mario & Sonic at the Olympic Winter Games as a VIP where he shows up in Dream Events during December. Unlike most VIP characters, you receive 300 star tokens for finding Santa rather than the standard 100. A Santa hat, coat, mittens and boots can all be purchased in the boutique and then fashioned on a Mii.

Trivia

 * During a scene of Sonic Christmas Blast, Santa's gloves are white, instead of green.
 * In Sonic Christmas Blast, Santa is voiced by Jay Brazeau.
 * The colors of Sonic's shoes is actually based off of Santa.