Hmm… Was it pi over infinity or…
— The Ultra-Mech scientist thinking to himself on Quartu, R&C

The Ultra-Mech Scientist was a friendly scientist who was hired by Drek to design and mass-produce the Ultra-Mech Unlimiteds for the Blarg. He accomplished this by designing the enlargement device that took smaller robots to transform them into massive, heavily-armed killing machines within mere seconds. Unfortunately, he failed to realize that Drek intended to use these Mechs for evil purposes and worked to destroy his creation.

The Scientist met Ratchet and Clank on Quartu while trying to destroy his device. The three men realized that the existing Mechs had to be destroyed, so the Scientist allowed Clank to use the device to transform into Giant Clank. Clank easily defeated all of the Mechs, and to show his gratitude the Scientist programmed the device to respond only to Clank's specific circuit pattern. He also gave them the Infobot for the Hologuise on Kalebo III. It was possible that he was related to (or at least was the same species as) the scientist in Going Commando, who was frozen in an ice cube on planet Barlow, where he sold the Thermanator for a 1000 bolts.