Santa Claus (also known by many other names) is a legendary figure originating in Western Christian culture who is said to bring gifts during the late evening and overnight hours on Christmas Eve. This character features in the story.

Examples:
In tz1985e1x13a "Night of the Meek", Henry seemed to metamorphose into Santa Claus himself.

References:
https://en.wikipedia.org/wiki/Santa_Claus