Hoopy the Hoop

In Portal, Hoopy the Hoop was a hoop fallen from the

As joked about in an interview with Valve on "Opening The Portal: Exploring The Game's Development", said they never expected "The Cake is a Lie" to become such a huge hit. The developers said they expected, if anything, that Hoopy the Hoop would become the meme derived from Portal.

Erik Wolpaw jokes, "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."

In Portal 2 it became a canon joke, by reappearing in some chambers (See "Portal 2" Below.).

Hoopy's in-game object names are glados_gib_10 and glados_debris_05.

Portal
Hoopy the Hoop rolls across the screen

Portal 2
Hoopy is known to appear in a few places within Portal 2. Its earliest known appearance is in GLaDOS' ruined chamber, where it lays slightly to the left of what could be described as GLaDOS' head; its second known appearance is underneath a floor panel in Test Chamber 02. Hoopy's fourth appearance is in one of the randomly-chosen exit corridors in chambers created with the Perpetual Testing Initiative. It is seen by noclipping into the ceilings of the exit corridor, although it doesn't appear in every one.

Trivia

 * Hoopy appears multiple times as an easter egg in Portal Stories: Mel.