Most TV shows have music, opening themes often included whole songs (until Lost ruined it for television musicologists everywhere). At times, feeling puckish with their funds, shows have had special holiday openings which spoofed their own music. These may exist in the hundreds. I have a few.
“The Rugrats Christmas Theme” doesn’t sound much like their opener, but it’s polka fun.
“Dora the Explorer Christmas Theme” also reeks of bells, not much castanets. Love the samba in the original.
“It’s a SpongeBob Christmas! Theme” sounds more like their music, and we’ll get to that special later. Lots of songs!
“3rd Rock from the Sun Christmas Theme” sounds very like their original, with a slight twist.
Ditto with “That ’70s Show Christmas Theme” which only jingles some bells.
Bear McCreary’s carol-sized minimalist intro for “Eureka Christmas Theme” goes all out, for about ten seconds. Thanks, Bear, now go count your Galactica residuals.