How to get Vicious Saddle: After you fill your progress bar up once, earning the Vicious War Spider, you'll get a Vicious Saddle every future time you fill up the bar, which can be turned in for many mounts!
The mounts require a total of 2400 points. 2v2 wins give 10 points (0.33%), 3v3 wins give 30 points (1%) and rbg wins give 60 points (2%). You can use the following macros to check your progress.
Alliance Mounts you can purchase with Vicious Saddle:
Reins of the Vicious Warsaber
Vicious War Ram
Vicious War Mechanostrider
Vicious War Elekk
Reins of the Vicious War Steed
Vicious War Bear
Vicious War Lion
Vicious War Turtle
Vicious War Fox
Vicious Gilnean Warhorse
Horde Mounts you can purchase with Vicious Saddle:
Reins of the Vicious Skeletal Warhorse
Vicious War Raptor
Vicious War Kodo
Vicious Warstrider
Horn of the Vicious War Wolf
Vicious War Bear
Vicious War Scorpion
Vicious War Turtle
Vicious War Fox
Vicious War Trike
Vicious War Spider, the mount rewards from 9.0 Rated PvP Incentive - Shadowlands Season 1 Saddle, will be purchasable at the end of the expansion.