Appearance in Portal
The Weighted Companion Cube is a pseudo-character that appeared in one of the many memorable levels in Valve's first-person puzzle game, Portal. The Weighted Companion Cube is a well known meme among most gamers on the internet.
Despite being similar in most respects to other puzzle-solving cubes in the game, GLaDOS introduced a personalized version of the cube in the beginning of the 17th level, with pink-coloured heart decals on each face, and the player, Chell, was told to take care of it throughout the level.
"This Weighted Companion Cube will accompany you through the test chamber. Please take care of it."
- GlaDOS, start of Test Chamber 17
While being in every way an inanimate object, the Cube is widely considered to be a character due to the charming way it was presented in the game, and the emotional attachment the player builds towards it by the end of the level. This was also helped by GLaDOS's constant reminders to the player that the Cube is not alive, which actually does the opposite, making the player see it as little more than a simple cube.
"Your Aperture Science Weighted Companion Cube will never threaten to stab you, and in fact cannot speak. If your Weighted Companion Cube does speak, please disregard its advice."
- GlaDOS, one of her constant reminders given to the player throughout the game
After successfully reaching the end of the level, it is revealed that the player would not be allowed to bring the Cube along with them to the next level, with GLaDOS again contradicting her claim of the Cube not being alive by telling the player to 'euthanize' it in the nearby incinerator. Upon dropping the Cube into the incinerator, the player is congratulated by GLaDOS:
"You euthanized your faithful Companion Cube more quickly than any other test subject on record. Congratulations."
- GlaDOS, after the player 'euthanizes' the Weighted Companion Cube
Effect on Previous Test Subjects
In some of the hidden rooms in Portal, mad scribblings dedicated to the Companion Cube can be found on the walls, and pictures of it pasted over the faces of people in photographs, implying that some previous test subject(s) may have gone mad, and grown too attached to the Weighted Companion Cube.
In Portal: Test Subject, it is revealed that the identity of the mad scribbler is Doug Rattman, a schizophrenic who uses the companion cube to project his conscience.
The Weighted Companion Cube appeared very briefly in the E3 2010 trailer for Portal 2.It makes it's return briefly in Chapter 2 - Chamber 7. In this test chamber the cube is needed to progress and complete the chamber, when you first try and pick up the cube GLaDOS will fizzle the cube away, GLaDOS will then drop another cube and repeat the process and remark that they have warehouses full of the things. At the end of the test the player then has the option of taking the companion cube with him outside of the test chamber due to the disintegration beam being "broken", there is an achievement available for doing this. However as you approach the lift GLaDOS will fizzle the cube and say
"I think that one was about to say I love you. They are sentient of course, we just have a lot of them."
- GLaDOS upon destroying the cube after you successfully get it out of the test chamber.
The last image of the game is that of the Weighted Companion Cube being shot out the exit door of the Aperture Science Enrichment Center, burn marks on the cube imply it is the same cube from the original portal.