Hoo Hah is a term used to describe a combo done by Diddy Kong in
Nintendo's Super Smash Bros. For Wii U and Nintendo 3ds. Hoo Hah was received quite controversially among the the Smash Bros competetive play community because of it's overpowered nature. The combo was performed by using a down throw to an up-aerial move often causing crowds to shout out the name they had given it - the Hoo Hah. Due to it's earlir mentioned overpowered nature, it became quite infamous, and so did Diddy Kong players alike.
The combo was ultimately removed in an update patch for the
game by Nintendo April 15th 2015. Since it's removal, the Hoo Hah has become a fairly
popular meme.
Examples of how it's used
Example 1: Oh man! The Hoo
Hah is so damn OP (overpowered)
Example 2: You should've
seen Hungrybox getting Hooh
Hah-ed by Player 1, he popped off his chair!