Someone who leaves a turd behind in a toilet, usually public. Usually, this "gift" is well wrapped with toilet paper and so large that the toilet cannot be flushed safely.

Like Santa Claus, Shit Santa is legendary and never seen. Unlike Santa Claus, Shit Santa operates 365 days a year, and no one looks forward to his visits.
Don't use that toilet, dude. Shit Santa left a real nasty one.
by Tuftskins April 30, 2009
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