C. Petrus was the name of a Human Starfleet officer who served during the mid-22nd century.
In 2154, he was listed as a Flight Software officer on the dedication plaque of the Columbia NX-02. (ENT: "Affliction", dedication plaque)
In January of 2155, he was listed as a Propulsion officer on directory placards at Starfleet Command's Fleet Operations Center, Sol Sector. His office was located in room #4227. He was also listed as a Thermal Operations officer on directory placards at Starfleet Command's Fleet Operations Center, Sol Sector. His office was located in room #4306. (ENT: "Demons", directories)
This character was only mentioned in writing.
They were named after Enterprise visual effects assistant editor Christopher Petrus.