|Alignment||Neutral (possibly evil)|
|First Appearance||No No Nanook|
The Brain Aliens are aliens who are actually disembodied brains and stomachs attached to other aliens and robots who appeared in the episode No No Nanook.
They are quite friendly to beings who resemble themselves although they seem to have a low tolerance for humans, casually feeding them to their pet or simply probing them.
The aliens were apparently travelers who enjoy visiting Earth while also collecting humans for their pet Ridley to eat. After Earth's gravity was destroyed by the Anti-Gravitational Nuclear Fragmentation Device, Hector, Boskov and General Skarr were abducted by the Brain Aliens and they had their robotic probe feed the fearful Skarr to Ridley much to Hector's horror and then had their probe take Hector directly to them. Upon meeting them Hector was both shocked and amazed to see others like himself with the Brain Aliens even calling him one of their own. Hector then realized that he wasn't alone in the universe and that bodiless brains were common throughout the universe. Hector now happy to not be a misfit happily sings with his new friends as their saucer travels to parts unknown.
- They are simply referred to as "Aliens" in the credits.