Rexorian

The Rexorians are a blue eneergy based lifeform from the planet Rexor IV, they feel no positive emotions like love, caring and devotion, only negative one slike hate of violenece (though in one seen case this may not be true), they are agressive towards humans killing a number of them as soon as there space craft landed on there home world, they have the ability to metamorph, join with another living organism and inherit there dna and memories making them very hard to spot.