The comet is a special comet that comes once every 365 yuletidian cycles. Wander and Sylvia are caught by this meteor in the episode "The Gift", they use this as a transportation in order to send gifts to the characters he met from the past season.
The comet looks like the average comet on the outside: a light blue icy solar system body. On the inside, however, while the color remains the same, it looks like a type of wormhole.
- "The Gift" (First appearance)