Sure-Footed

Your footing is secure in unstable terrain.

Prerequisite: Quadruped animal or magical beast.

Benefit: You gain a +2 bonus on Acrobatics checks to keep your balance and Reflex saves to avoid falling. You can move at a normal speed on steep slopes and stairs and do not risk falling when running or charging downhill.

Normal: Moving uphill costs 2 squares of movement to enter each square of steep slope. Running or charging downhill requires a successful DC 10 Acrobatics check (or DC 10 Ride check for mounted characters) or you risk falling (Pathfinder RPG Core Rulebook 428).

Source: Animal Archive