A snowball made of disgusting snow/slush from the side of the street mixed with a generous portion of urine. Often this snowball is thrown at someone unexpectedly.
Dude I hit that nerd with a yellow surprise!
by Dr. Deejay Narnar January 13, 2011
When you wake up, and discover that a Chinese man is engaging in sexual intercourse with you.
Last night I got a yellow surprise. It scared the crap out of me!
by Petey B. May 23, 2006