The man known as The Brain was an eccentric gang leader who wore a hat made to resemble a human brain. He was a slender man with freckles, small eyes and dark hair.
The Brain played the ocarina, which he sometimes used as a way to send non-verbal messages to his co-horts. He had previously been convicted of two murders, but had been released on parole.
Encountering Dick Tracy
The Brain had employed Onyx Fencer to hide much of his stolen money and goods. Fencer's home was destroyed in a hurricane while Fencer had been arrested for his association with Big Brass and all of the money and merchandise was lost. Big Brass' girlfriend Crystal posted Fencer's bond, which led the Brain to believe that an additional cache must exist. Brain and his gang attempted to kill Fencer, but he survived. Fencer later took his own life.
Brain and his gang abducted Crystal and had her lead them to the hidden cache of money. They then killed her. Their truck had been damaged on the drive to the secluded area, so Brain and his gang hijacked a passing car. Their victims were Vera Alldid and Sparkle Plenty, who reported the theft to Dick Tracy. Alldid was not able to describe any of the men, but he did take note of the Brain's unusual hat. Tracy used this to get his first clues to the Brain's identity.
Brain planned an elaborate party for his former cellmate Dee Lord (also known as "Pug") who was being released from prison. At the party, Brain began choking on a chicken bone. His gang was unable to help him and tried to rush him to a doctor. Brain's girlfriend Toots drove the car through a red light and struck a cement truck. The collision knocked Brain into the windshield, and the force of the blow dislodged the chicken bone. Brain was grateful and the gang fled, leaving Toots' car at the scene of the collision.
Toots' residence was discovered by police and officer Groovy Grove went to arrest her for leaving the collision. Brain struck Grove from behind, knocking him unconscious. Brain and his gang then fled, leaving Toots with the unconscious Groovy. Tracy and Lizz soon arrived to follow up on Groovy's arrest, and Toots was taken into custody. She informed the police where the Brain's hideout was.
While trying to escape from Dick Tracy and Sam Catchem, Brain and his gang drove into a train tunnel and were killed when they crashed into a freight train (January 26, 1975).
- The Brain appears on the cover of The Complete Dick Tracy Vol. 28.
- The Brain's gang consisted of himself and three other men. Two of these men were identified by name (Stubby Chinz and Purce). The third man was never named.
- The Brain used Onyx Fencer to hide his money and stolen goods in much the same way that Big Brass had, but it was never stated that the Brain and Big Brass knew each other.
- A character called "The Brain" had previously appeared in a 5-episode arc of the 1950s live action Dick Tracy TV series starring Ralph Byrd. The Brain was played by Lyle Talbot (who had also played Big Frost and 88 Keyes). That character predates the Brain from the comic strip by nearly 25 years, and there does not seem to be any connection between the two.