You must learn a special skill to tame Blood Beasts. It is taught by a Blood-Soaked Tome of Dark Whispers, a guaranteed drop from Zul in the Uldir raid on Normal Mode or above (i.e. not LFR). Once learned, this skill is account-wide.
2 possible appearances:
Location & Notes:
Located in Primal Wetlands, Nazmir. Blood ticks with this ID are only present on days when the world quest Scorched Earth is up. They're found in groups nearby tameable bloodticks with the same name.