Stench
Source Alien Core pg. 210
(aura, olfactory) A creature entering the aura or starting its turn in the area must succeed at a Fortitude save or become sickened 1 (plus slowed 1 as long as it's sickened on a critical failure). A creature that succeeds at its save or recovers from being sickened is temporarily immune to all stench auras for 1 minute.