Synopsis by Hal Erickson
The plot of The Brain from Planet Arous has something to do with a huge floating brain which takes over the body of nuclear scientist Steve March (John Agar) as the first step in its takeover of the earth. Tipping off the fact that March is not himself are his strange eyeballs and his rather violent mood swings. Additionally, the arrogant alien brain occasionally leaves Steve's body to brag about its superiority. Meanwhile, a "policeman brain" from the villain's home planet hides out in the body of March's dog, awaiting the chance to arrest the renegade graymatter.
alien [not human], possession, attack, brain, evil-possession, good-vs-evil, invasion, parasite, scientist