The Alien Brain Boss is a villain from the animated series Courage the Cowardly Dog. He is an alien that arrived in Nowhere inside a UFO. He appears in the episode "Car Broke, Phone Yes", along with the Alien Brain Visitor.
The Alien Brain Boss can speak in complete sentences unlike the Alien Brain Visitor or any of the other aliens. The Alien Brain Visitor might have the ability to move the ship since he was able to pick up the Alien Brain Visitor at an alien bus stop. However, he later orders the Alien Brain Visitor to start the engine.
The Alien Brain Boss despises Earth especially the humans who resides there. He said that since humans have arms, legs, and other limbs and organs he sees it as something idiotic. Like Muriel, who has lost her friendliness, the Alien Brain Boss can be rude and disrespectful.
After arguing with Muriel, the brain was caught in an explosion set by Courage and is presumably dead from the blast.