pf2e.fyi
From Pathfinder Lost Omens Cheliax, Infernal Inheritance, which isn't enabled.

Nidarrmar Steed

FEAT 6
UNCOMMONCHAMPIONCOMMANDERDRUIDRANGER
Prerequisites horse animal companion
Access You're from Nidal.

Your steed was bred from the steadfast stock of the Atteran Ranches. Your horse animal companion reduces any penalties to its Speed by 10 feet, and if it would gain the Fleeing or controlled conditions, you can choose to have it instead become Slowed 1 for the same duration.

Special Your horse animal companion can't gain the benefits of a different breed, such as Chiardmar Steed.
Pathfinder Lost Omens Cheliax, Infernal InheritanceORC