Tenza

Tenza were a species of alien chameleons with powerful psychic abilities.

Life cycle
The Tenza were an alien species with similar behaviour patterns to a cuckoo bird. Shortly after birth, they drifted in space looking for the nearest habitable world and a family that wants a child (but can not naturally achieve one). After locating a such a family, the Tenza infant would adapt itself to perfectly suit its environment and alter the surrogate parent's memory and the memories of those around them to believe the child was always part of the family.

After that the alien would live out its life as a member of that species, without consious realization of their true nature.

However, should a Tenza rejected by their surrogate parents, their telepathic abilities would start to play havoc with their environment. This was the case with George, a Tenza who has disguised himself as a human child of Alex and Claire, who believed his parents wanted to get rid of him because they were struggling to help him cope with his phobias. This caused his powers to bring his phobias to life in a doll house that was governed by the Peg Dolls, who would terrorise him and abduct anyone who terrified him. (DW:Night Terrors).

The matter was resolved when the Doctor was able to help George's father realise that, despite what George was, there was still a paternal bond between them.

Culture
to be added