For the real universe counterpart, see Phigus Simenon.

In the mirror universe, Phigus Simenon was a Gnalish member of the Terran Rebellion. An engineering genius, in 2333, he was working on a new propulsion technology beyond the abilities of even the Klingon-Cardassian Alliance. That year, he was killed in a battle with a Klingon bird-of-prey. Posthumously, he was credited with much of the Rebellion's success. His colleague Montgomery Scott devised a strategy to replace him with the "real" universe's Simenon, which was unsuccessful. (STA novel: Three)