Santa Claus

From Tardis Wiki, the free Doctor Who reference

Santa Claus or Father Christmas legendarily distributes presents to good children on Christmas morning under the tree. He plays an important part in the Christmas tradition on the planet Earth. The origin of Santa stems from a number of different centuries-old traditions, with the most iconic version of Santa being finalized in the early 20th century.

Appearances

In order to deliver presents to all children in a single night, Santa uses time loops and clones of himself. (ST: The Man Who (Nearly) Killed Christmas)

The Doctor visited Santa Claus in his workshop and helped save Christmas. (TVC: A Christmas Story)

A later Doctor warned Santa of a future where the toy workshop spanned over 2000 worlds and the fabric of space was being torn upon by his time looping. A solution was found involving a fleet of robot Santas and newly calculated, more stable wormholes.(ST: The Man Who (Nearly) Killed Christmas)

This adventure may well have happened in the Land of Fiction.

Santa helped Iris Wildthyme find Panda. (BFIW: The Claws of Santa)

References

Although the Sto history of Santa is garbled, historians have indicated that some elements of the Santa legend originate from a more sinister source than the "jolly old elf" best known to the people of today.
Santa Claus