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A homeless person that lurks in the shadows, normally in alleyways, and appears seemingly out of nowhere to ask for change or other items.

Shadow Bums can appear day or night, but mainly strike when you think the area is free of homeless.
"I checked around for bums and everything. I thought the area was clear, but then out popped a shadow bum from behind the building and he asked me for a cigarette!"
by wayoutofplace April 23, 2008