|Set||71203 Level Pack|
|Companion Cube||Laser Deflector||Gold Heart Emitter|
The Weighted Companion Cube (often referred to as the Companion Cube) is a recurring object in the Portal 2 universe. It appears almost identical to the Weighted Storage Cube but with a pink heart replacing the Aperture Science logo.
In Portal, the Companion Cube was given to Chell in order to aid her in completing Test Chamber 17. In order to progress through the exit at the end of the chamber, the cube was dropped into the incinerator to be "euthanized". GLaDOS used this moment to taunt Chell during their confrontation. However, the Companion Cube can be seen prior to the end credits next to the Cake, suggesting that it survived.
The Companion Cube makes a prominent appearance in the Portal 2: Lab Rat comic, in which it speaks with protagonist Doug Rattmann. This appears to reference Portal, in which GLaDOS states that the Companion Cube cannot speak and, if it does, its advice should be disregarded.
In Portal 2, GLaDOS briefly torments Chell by repeatedly destroying Companion Cubes in Test Chamber 7. It is at this point that GLaDOS claims that the Cubes are in fact sentient, which suggests that they possess some level or rudimentary intelligence similarly to Turrets. The Cube also makes an appearance in the Co-op campaign but is inaccessible, preventing the player from interacting with it. After Chell leaves the facility upon completing Portal 2, a scorched Companion Cube is ejected after her. This Cube is not the newly-designed Portal 2 Companion Cube, but is the same as the cube from Portal. Valve said that it's the exact same cube the player euthanized in the first Portal, that is given back to her. The Companion Cube in Portal 2 hums an excerpt of Cara Mia, which can be heard when it is nearby.
- The Companion Cube is a unique gadget due to its Weight Switch ability that can activate Cube Switches.
- The Companion Cube is the only gadget to have the Weight Switch ability in all its rebuilds.
- Since it's very hard to move it around in-game by carrying it, you can upgrade it so it can follow you around, similar to NPCs.
- It is summoned from the Locate keystone to solve a puzzle in the E.T. The Extra-Terrestrial World.