Telepathic, shape-changing natives of the rogue planet Dakala, hunted for sport by the Eska and protected by Archer's crew in the Enterprise episode Rogue Planet.
The Wraiths appear in the Enterprise episode Rogue Planet. They live in the hot-spring jungles of Dakala, a world drifting through space without a star. In their natural state they look like large slugs, but they can take any form and read the thoughts of other beings.
The Enterprise crew meets a party of Eska, who visit Dakala regularly to hunt. Their favourite quarry is the Wraith, precisely because it can sense a hunter's fear and change shape to escape. The Eska do not consider it a person.
One Wraith approaches Archer in the shape of a woman drawn from a poem he loved as a boy and asks for help. Phlox prepares an agent that hides the chemical trace the Eska use to track the creatures. The hunters leave empty-handed, never knowing why.