Unused look : This look is not available in the game.
Zandalari hunters automatically know how to tame Direhorns. Hunters of other races must learn the skill from an Ancient Tome of Dinomancy which is a rare drop from Zandalari Dinomancers on the Isle of Giants in Pandaria. This skill is NOT account-wide.
This is the original blue direhorn colour, which was added in the Patch 5.2 test realm but was sadly removed and replaced by the current blue direhorn look before release. Hopefully it could be restored to the database and used somewhere in the game.
*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.