Ashen Stars: The Dark Within
Beings from a higher dimension, Qu’rak sometimes enter our reality to feed on exotic high-energy particles. Being four-dimensional entities, they can “bloom” at will anywhere within our space, and leave the same way. They have been observed to kill beings saturated with high-energy particles in the process of feeding.
It is unknown if Qu’rak have a true form. They have been observed to manifest as both an amorphous area of distorted space, and as a humanoid form. In either form, they are transparent, but appear to warp the space around them.
They are able to be damaged if entangled in high-intensity electro-magnetic fields – certain field configurations act as a snare, trapping them temporarily within our reality.