https://freesound.org/people/blazecon0/sounds/99222/ (Attribution 3.0)
mob_horse.1.ogg

https://freesound.org/people/Gingerhoney/sounds/655070/ (Attribution 3.0)
mob_horse.2.ogg

https://freesound.org/people/GoodListener/sounds/322445/ (Attribution 3.0)
mob_horse_whinny.ogg