A Holiday Elf

"Do stop grousing Black, you did state you wanted to help did you not?" Severus asked smirking at Sirius's attire, "the children are waiting and you make a perfect elf."
"I will get you back for this Snape." Sirius snapped.
"Yes, I do look forward to you trying." Severus replied.

Severus Snape's way to wish others a Merry Christmas, with help from Sirius Black!