The top head never speaks to my knowledge and also seems to have the mind of a child, the body seems primarily controlled by the second more intelligent head though it appears they can alternate.

No powers aside from being the muscle which even then seems limited.

Biologically I imagine both heads share senses but aren’t 2 separate entities, the top head is a pseudo head that exhibits behaviour associated with the right hemisphere of the brain which specializes in emotion and creativity among other things thus it reacts accordingly such as when psyphon smacked the teeth out him and he cried essentially expressing the real emotions of the individual.

For new powers let’s turn strength, durability and pain tolerance up and acid saliva from the stomach head.

Psyphon in omniverse was super strong despite his lanky build all thanks to his cybernetics so we’ll say it takes the same kind of force for this alien to feel pain.

Jason had cellular regeneration, weapons mastery, wicked lung capacity, and sometimes telekinesis but we’ll leave that one out.

Just like Jason putting him down is no easy feet when he can power through most attacks without flinching and 2 heads means you’d have to knock both unconscious otherwise the head that’s still awake prevents the other from going into la la land.

Interestingly the 2 heads might make telepathy impossible.

So I had an idea for a TummyHead transformation (species unknown)