There's a chance this beast will appear when you use an Elusive Creature Bait in some watery areas of The Waking Shores and some coastal areas of The Forbidden Reach. To create Elusive Creature Bait you must have levelled Dragon Isles Skinning to the point where you can select the Bait Crafter specialization (see your skinning journal inside your professions panel) and spend at least 10 points of Knowledge in it.
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.