| effective veffective = Crushing (Very), Trauma (Very) | ineffective vineffective = Nature (Very)

 '''[[The Geyser Slug''' is a massive [[Poison Slug]] living in an Oasis in the [[Ilmari]] Desert. The slow-killing poison attacks it delivers can sap an opponent dry. 

; [[{{MOB Location| area = Ilmari]]: | location = Found in the oasis near Bonnie & Arlan's Shop.| health = 4018| armor = 272| rage = 1295}}