Invisible alien

This unnamed species was part of a spaceship crew that was trapped between real space and the time vortex due to engine trouble with the spaceship.

Biology
The species had tiny, ovoid bodies with vestigial limbs. They were telepathically linked to their spaceship. (PROSE: Doctor vs Doctor)

History
Due to their telepathic link to the spaceship's computer, once the engines failed, the crew died as well. When the Ninth Doctor and Rose signalled the ship with the standard galactic code, the computer teleported them up, and they found three bodies on board. (PROSE: Doctor vs Doctor)