Herself, an Elf
Herself, an Elf is a script-based story by John Berry, probably set around season 2. Feeling guilty about her annual recycled gifts (which are literally recycled; she tracks down the exact gifts in Jake, Helen and Quinn's closets and gives them again), Daria allows Jane to get her a job as an elf for the mall Santa. When the first Santa quits, the new one, Stan, forms a bond with Daria. When he later has to leave, Daria finds that she has to run the "Santa" attraction by herself, and becomes a local celebrity in the process.
Herself, an Elf at Outpost Daria (via Wayback Machine)