From Warhammer 40k - Lexicanum
The Phosiab are a sentient Xenos species, who have joined the Tau Empire.
They can see reality in nine dimensions and slip through the void unharmed. These abilities are a boon to the Tau Empire's extra-orbital construction.
- 1: Codex: T'au Empire (9th Edition), pg. 8 — The Greater Good: Alien Auxiliaries