Conjure Mount

you release a primal whistle that all within 1 mile of you can hear. when cast, a white horse canters from the sky and stops right in front of you. This horse can seat 3 people of medium size, 6 of small size, 12 of tiny size, and 1 of large size. the horse has a running speed of 100 and doesn’t need rest, food, or drink. it stays with you until dispelled or if it takes any damage. It has an AC of 15 

At Higher Levels:  the horses ac increases by one for every spell slot used above 4th