DR.RATTMAN

Doug Rattmann, commonly nicknamed as the Rat Man, was a scientist at the Aperture Science Enrichment Center. Prior to the events of Portalwhile GLaDOS began flooding the entire facility with neurotoxin, Rattmann is the only known employee to have survived. A paranoid schizophrenic, he is dependent on anti-psychotic medication as a means of keeping him sane.

Rattmann does not appear in-game in any form, instead leaving behind paintings and murals which can be found throughout the single-player campaign of Portal 2.