First appeared in Detective Comics #469 in 1977 and was created by Steve Englehart and Walt Simonson. Dr. Alexander Sartorious was a nuclear scientist who became Doctor Phosphorus after being present in a nuclear plant during a meltdown.
Batman Villains Who Should've Appeared on Batman The Animated Series (1992)
Here the rules: Pick any villain who never appears on BTAS. Do not pick any villain that does not existed yet (example: Professor Pyg) or villain that is too violent for the series (example: Victor Zsasz).