A turd left in the top tank of a toilet. Often undiscovered for weeks, leaving an unmistakable odour that no amount of air freshener can neutralize.
Liam hated his filthy, selfish housemates; so when he moved out he left them a sleeping hippo as a parting gift.
by Ice J February 27, 2010
Sleeping hippo
A sleeping hippo is when When you look into a toilet bowl and there is a big fat round turd sitting there floating with no toilet paper in sight
by Chimpokaziza April 8, 2023