Druid talent · row 1 of Feral Combat, from level 10 (5 with Talented 5/5) · Physical

Ferocity

Reduces the cost of your Maul, Primal Bite, Swipe, Claw, and Rake abilities by 1/2/3/4/5 Rage or Energy.

Game files · build 1.60.1.70245Read from the WoW Forever beta client, build 1.60.1.70245.

Compared with Classic

Classic tooltip

Reduces the cost of your Maul, Swipe, Claw, and Rake abilities by 1 Rage or Energy.

What Blizzard said about Ferocity, each line checked against the files.

Matches the files
All talents referencing Mangle now reference Primal Bite.
The files In build 70009 the Ferocity (16934) and Berserk (417141) tooltips switched from Mangle to Primal Bite. No Druid talent in build 70245 mentions Mangle.
Ferocity Berserk Development Notes, September 24
Matches the files
Ferocity: Critical strike bonuses to pets decreased, but now also benefits Hawk summons.
The files Hunter Ferocity (19598) gives pets and hawks 2/4/6/8/10% crit in 70245; Classic gave pets 3/6/9/12/15% (tooltip and talent curve).
Ferocity Class deep dives: Hunter and Druid
Matches the files
Ferocity: Now also applies to the new Primal Bite talented ability.
The files Druid Ferocity (16934) lists Maul, Primal Bite, Swipe, Claw and Rake, and its class mask includes Primal Bite's flag.
Ferocity Primal Bite Class deep dives: Hunter and Druid