Doug Rattmann



Doug Rattmann, better known as the 'Rat Man', is an Aperture Science employee who survives GLaDOS's attempt to poison every employee in the facility with neurotoxin when she is switched on. He does not appear in-game, instead leaving behind paintings and murals which can be found throughout the Aperture test chambers in Portal and Portal 2. A paranoid, he is dependant on anti psychotic medication to keep him sane.

Aperture Science career
In the Portal 2: Lab Rat comic he is revealed to be an Aperture Science employee who worked on the Handheld Portal Device.

Portal
Delusional, running low on medication and traveling with a talking Weighted Companion Cube, he watches from the shadows as Chell is tested by GLaDOS. Although never seen in Portal, his 'dens' can be found by the player, containing crude bedding, empty cans of beans and scribblings and dioramas on the walls. It is in one of these dens that the words 'The cake is a lie' is found scribbled on a wall, resulting in the well known meme.

Trivia

 * Doug Rattmann was behind the Aperture Image Format, used in the Portal ARG.
 * He can be heard rambling in one of his dens in Portal 2.