Gnome, Goblin and Mechagnome hunters automatically know how to tame Mechanicals. Hunters of other races must acquire the skill from a Mecha-Bond Imprint Matrix, crafted by Engineers who have at least 1 skill point in Legion Engineering.
Found at limited locations around the Citadel. Two can be found flying by the western edge of the main area and a third can be found sitting on the ground in a plaza further east.
Level scaling: 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.