Thought-forms were linked with a host, sharing thoughts with each other. Generally, the thought-form took on an inconspicuous form except when hunting. When hunting, they would take the appearance of translucent material, between gas and liquid, with star-like lights inside. They were also capable of passing through matter. Thought-forms needed cellular matter to maintain their form. Anything they couldn't eat would be excreted as a slime. Thought-forms were also repelled by the undead Owen Harper. (PROSE: SkyPoint)