Nervoid
From Tardis Wiki, the free Doctor Who reference
The Nervoids were, according to the Fourth Doctor, "one of the most aggressive races in the galaxy". Although they were geniuses, physically they were weak. They created armour that would attach itself to the dominant species of a planet, conscripting individuals for their battles.
The Doctor and Sarah Jane Smith encountered one piece of armour in Papua New Guinea that had attached itself to a crocodile. (PROSE: Conscription)
