The Tetraps are large, lumbering, shaggy creatures from the planet Tetrapyriarbus. They have four eyes, one on each side of their head, giving them a four-way view of the world. They are able to restrict their view to only one direction, if they so desire. They also vaguely resemble bats, in that they have bat-like wings and rest hanging upside-down in an eyrie. Their hands and feet are clawed.
Tetraps feed on plasma, although there is no indication that they kill humans to obtain it. Their speech is slow, and they seem capable of uttering only a few syllables at a time. Their tongues are forked and seem to be able to inject some kind of venom that paralyzes their victim.
They make good servants if treated well, but they are very capable of thinking on their own. Tetraps can manipulate weapons and operate doors. They can be confused if they are showered with a glittery substance like confetti; it seems to disorientate them.
