Loyalty: The rider can't fall of the yak. When the rider is unconscious, its will passes to the yak. Mountain hooves: The yak can move through steepe terrains of no more than 60 degrees.
Brave Yak: The yak charges in any direction. 1d10. However his long hair covers his vision. It must make a dexterity check of over 5 in in order to succeed (this means one has to roll from 15 to 20), otherwise, It causes half of the damage. (The yak will not cooperate if he/she is in bad temper).
Shared damage: The loyal yak uses its body in a way it absorbs 1/2 of bludgeoning damage caused to the rider. (The yak doesn's react if he is in bad temper.)
Giant Yak: If the yak is fed with ten rations of Khorkhog*, it metamorphoses into a giant yak, being able to transport 5 people. His giant extremities allow him to trout at a speed of 80 feet. The ammount of milk produced also increases to eight portions that together have an 8d4 healing power. The effect lasts for a day, to repeat it it must be fed 10 rations of Khorkhog.
Beauty: Everyone at 30 ft around the yak come close to him to worship him, feed him, and offer money and/or cattle in exchange of it.
A very loyal beast of the himalayas with hughe lungs to overcome exhaustion at high altitudes. It consumes only 1% of its bodyweight each day in contrast to cows that havee to consume 3%. It also produces a very nutritious milk that some believe to have healing properties. Three properties resume its utility for an advenurer: Resistant, loyal and nutritious. The yak has the cost of three camels or 600 gp. It must drink at least 5 gallons of water per day, otherwise it gets into a bad temper.
Advantage on the mountain (3000-6000 meters over sea level)