[1] He was best known for having provided the voices of Dr. Weird and Steve on the animated series Aqua Teen Hunger Force, and Zorak and Moltar in Space Ghost Coast to Coast, replacing Don Messick and Ted Cassidy, who originally voiced the characters in the 1960s series Space Ghost.

In addition to being the show's principal animator, it was also his idea to have Zorak and Moltar be Space Ghost's sidekicks.

[3][4] Croker served as an animator for Aqua Teen Hunger Force and its 2007 feature film adaption Aqua Teen Hunger Force Colon Movie Film for Theaters.

[3] Croker provided the voice of Young Man and other various characters in Perfect Hair Forever.

receives a transmission from Moltar saying he's returning to his home planet and will not be coming back, then boasting that he was the better Toonami host.