13 in human form, 14 in horse form
39 (6d8 + 12)
30 ft. (60 ft. in horse form)
Animal Handling +4, Insight +4, Nature +3, Perception +4
Common (Can't speak in horse form)
4
The horse master has advantage on saving throws made to avoid falling off his mount. If he does fall off his mount and descends no more than 10 feet, he can land on his feet if he's not incapacitated. Finally, mounting or dismounting a creature costs him only 5 feet of movement, rather than half his speed.
The horse master has advantage on attack rolls when he is mounted and avoids any opportunity attacks.
The horse master has advantage on Wisdom (Perception) checks that rely on smell.
The horse master can use his action to polymorph into a riding horse or back to his human form. His statistics, other than his size, are the same in each form. Any equipment he is wearing or carrying is transformed. He reverts to his human form if he dies.
The horse master makes two attacks.
Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 6 (1d8 + 2) bludgeoning damage.
Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 7 (2d4 + 2) bludgeoning damage.
The horse master can summon 1d4 riding horses once a day. The beasts appear within 90 feet of the horse master and obey his commands.