Necrolord-only initially. Can be created in the Abomination Stitchyard and summoned by the item, Construct's Best Friend. It will initially spawn as a guardian to the one whom summoned it, but can be released and made into a neutral NPC which can then be tamed.
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.