About:
Hoopy the Hoop is a meme that spawned from the ending of the first Portal game.

Origin:
At the end of the game once Spoiler Alert GlaDos is destroyed the game's main character, Chell sees a hoop land and fall flat infront of her.

Valve originally thought this would be the meme of the game stating,
"We thought we should have a warehouse full of Hoopy t-shirts and mugs and posters…we would watch that hoop roll by over and over again. That was the part of the game we were most proud of, and nobody cared." They had never anticipated that The Cake is a Lie would become the meme everyone would remember.

Hoopy does make some cameo appearances in Portal 2 but he is just a prop you can pick up.

Because of this many people don't know about Hoopy the Hoop and he has almost faded away into obscurity.