An aggressive species whose attack on a Federation colony provoked a grieving Douwd to annihilate every Husnock in existence.
The Husnock were a hostile and warlike species who attacked the Federation colony on Delta Rana IV, killing its 11,000 inhabitants. Among the dead was Rishon, wife of Kevin Uxbridge, a Douwd living in human form who had refused to use his powers to fight back.
Overwhelmed by grief and rage, Uxbridge wiped out the entire Husnock species, some fifty billion beings, with a single thought. The episode The Survivors reveals this in its final scenes, as Picard confronts the colonist about what he had done.