Cranio used to be one of the Sentry's greatest foes. He was a mad scientist who used a special helmet to gain mentally enhanced powers, and prided himself with being always three steps ahead of his nemesis. He ended up imprisoned at the Raft serving a sentence of 25 years to life. He was released under parole for good behavior, and since he couldn't find a job in the field of science due to his past record, he became a parking lot attendant.
The Sentry's former protégé Billy Turner was also living an ordinary life. When the Sentry's alter-ego Bob Reynolds returned to Billy's life, Billy became resentful since Bob confided with him that he could make use of a device called the Confluctor to travel to Sentry World, a pocket universe inside his own mind where he operated as the Sentry. Billy was jealous that Bob could relive his days of glory, and set in motion a plant to supplant him. After obtaining the personal notes of the professor that created the Golden Sentry Serum, Billy tracked down Cranio and convinced him to help him supplant Bob Reynolds. In exchange for synthetizing the serum to become the new Sentry, Billy would let Cranio become a supervillain again and prevent him from getting caught.
As part of their plan, Billy stole the Confluctor and gave it to Cranio, who traveled to Sentry World to ravage it, killing this world's versions of the Sentry's allies: Scout, Watchdog, and Sentress in the process. When he discovered that the Confluctor had been stolen, Bob turned into the Sentry in the real world, causing his normal self to be transported inside Sentry World. As soon as Cranio stumbled into Bob, he exited Sentry World and returned to the real world, but Billy forced him to go back and kill Bob while he injected himself with the Sentry Serum and combated the Sentry in the real world. Bob managed to dodge Cranio's attacks, and returned to the real world by merging with the Void and the Sentry.
With his three personas fused into a single entity, the Sentry defeated and killed Billy. Cranio tried to attack him mentally, but the Sentry quickly confronted him. Cranio attempted to defeat the Sentry by bringing him to Sentry World to take advantage of his mind state. However, the Sentry was unfazed since his mind as no longer fractured, and destroyed Cranio's helmet in the real world, pulling both out of Sentry World and leaving Cranio neutralized.
Helmet: Cranio possessed a helmet which allowed him to gain mentally enhanced powers, such as telepathy.
- Cranio's helmet included a container with three chimpanzee brains floating in formaldehyde. It didn't serve any practical purpose and it was only for show, since he was "Cranio the Tri-Level Mind."
- 5 appearance(s) of Cranio (Doug) (Earth-616)
- 6 image(s) of Cranio (Doug) (Earth-616)
- 2 quotation(s) by or about Cranio (Doug) (Earth-616)