Vile Peter

Vile Peter is an elf. He used to be one of Father Christmas' best helpers, but something happened and he turned bad. Since then, Father Christmas has kept him locked up in a cell at the workshop.

History
On the first Christmas Eve after Doctor Robotnik was overthrown, Vile Peter escaped from his cell and made his way to the Emerald Hill Zone. He used his magic to imprison the children of the Emerald Hill Zone in a special glass jar, and had captured half of the children in town when he was spotted by Sonic the Hedgehog. Peter did not know who Sonic was, but when Sonic correctly surmised that Peter had something to do with the missing children, Peter used some magic powder to knock Sonic off his feet. Sonic recovered quickly and charged at Peter, who suddenly disappeared. Fortunately, he was captured by Father Christmas (who had come to collect him) and stuffed in Father Christmas' magic sack before being taken back to his cell. All of the children were released.

Real world background
Vile Peter is based on the character of Zwarte Piet (literally Black Pete), a companion of Sinterklass (Saint Nicholas) in the folklore of the Netherlands and Belgium.