This rare snail can appear through most of Nazjatar. There's a chance of it spawning after Sea Spireshells and Prismatic Spireshells are killed.
Level scaling: In Shadowlands most NPCs will scale with the Hunter's level, within the constraints of their level range. Hunters can tame regular NPCs up to 2 levels higher than them, but can only tame elite NPCs of the hunter's level or below.