Hey guys! This is something we've seen y'all ask about and just wanted to share some insight to the Vicious Saddle mounts.
Currently, players can earn Vicious Saddles through the “Veteran of the Alliance” or “Veteran of the Horde” series of per-character achievements. We’re also working on some new ways players can earn Vicious Saddles in the next major content update, Tides of Vengeance.
Note that the Battle for Azeroth seasonal mounts will not be added to the saddle vendor until sometime after the conclusion of the final Battle for Azeroth PvP season. Until then, the only way to earn these mounts will be to actively participate in the associated PvP season.