Cake



The promise of Cake is introduced by GLaDOS as an incentive for Chell to complete the test chambers in the original Portal. It is referenced in many of the Rattmann's dens as a lie, sparking the "The Cake is a lie".

Trivia

 * The cake does not appear in Portal 2 as it did in Portal 1, Eric Wolpaw stated that it was removed because he and Valve are sick of the memes and have had enough of cake jokes.
 * The cake slice icon shown on the neon panels throughout Test Chambers in Portal appears in another Valve game, Alien Swarm, as the icon of the achievement "Perfect".
 * The icon has also appeared on the TF Birthday Noise Maker item's icon in Team Fortress 2, with the cherry removed.
 * The cake model was reused in Team Fortress 2 during its birthday mode with different textures.