Serpen Imperium

The Serpen Imperium is a nocturnal snake like alien from Alevita that has the rare power of speech and psychic manipulation. They gained this feature due to the density of the environment, having to press their heads near to each other to communicate when in denser areas.

They enter and exit and humans body through their mouths, residing at the beginning of their throats.

When they first take over a human's body, their iris will become green and have a serpent's slanted pupil before returning to normal after a few blinks.

The snake is a more solitary creature, not focused on having offspring or being in a pack (though will have offspring when necessary).

It is aggressive, stealthy and sadistic.

When not in Humans the snakes live in almost any condition.

They can psychically control human minds when in their bodies

They can momentarily control others or warp minds outside their host's body. It does this through the snake extending out the host's throat and having its head enter the targets mouth. It won't ever fully leave the host's mouth though, it's anchored in their esophagus.

The snake can access all the host's memories.

These snakes can act as parasites, controlling a human body fully, though preferring attractive female bodies. They are able to speak.

Once in control of a human, their tongue can be elongated to great lengths (somehow)

All food for both the snake and the human is digested by the snake, which eats it by extending out the host's mouth. It maintains its diet of small rodents or similar, but now eats more due to its host