A Preed emitting Nohadin gas
Nohadin gas is a poisonous gas emitted by Preeds and Dark Preeds in Metroid Prime 2: Echoes. The gas is highly corrosive. If an Ing takes possession of a Preed, the gas becomes even more dangerous. One scan found on a dead Luminoth in the Undertemple Shaft room of Dark Torvus reveals that the target was killed by Nohadin gas. The scan reads:
"Bioscan complete. Luminoth subject expired 1.86 decacycles ago. Target Luminoth was exposed to heavy amounts of Nohadin gas. This is likely the cause of death."