Born to a Scoutling Mother who had been curious if mixing with a particular depth-dwelling species would garner worthwhile results or not. The experimental pairing was found to be lacking, and he was tossed out of the Hive when the Matriarch decided his lack of water-dwelling traits made him unfavourable. His birth Hive was interested in fast swimmers, and he was decidedly, not a fast swimmer. The white urchin-like needles on his back hindered him in the water, adding additional weight that made it harder for him to swim. He'd be much better off with an above-ground Hive.
Poison Graephs are the water-oriented Graeph breed. They're called Poison Graephs because their burgundy-hued auras are poisonous. Just touching a Poison Graeph can cause paralysis for hours. They themselves are immune to poison, venoms, and toxins. Their blood (and tongues/mouth) are blue. While their poison aura is always active, they can choose whether it affects an ally or Hive-Mate or not.