From Pathfinder #176: Lost Mammoth Valley, which isn't enabled.

Megaloceros

CREATURE 4

The megaloceros is similar in form to the elk, but far superior in size. The average male's antlers weigh nearly 100 pounds and can be wider than his body is long. Megaloceroses stand up to 9 feet tall, weigh 1,500 pounds, and grow antlers over 12 feet wide.

Perception +10; low-light vision, scent (imprecise) 30 feet

Skills Athletics +13, Survival +10

Str +5, Dex +3, Con +5, Int -4, Wis +2, Cha +0

AC 21; Fort +13, Ref +11, Will +8

HP 58

Buck

DC 21 Reflex

Most monsters that serve as mounts can attempt to buck off unwanted or annoying riders, but most mounts will not use this reaction against a trusted creature unless the mounts are spooked or mistreated.

Trigger A creature Mounts or uses the Command an Animal action while riding the monster.

Effect The triggering creature must succeed at a Reflex saving throw against the listed DC or fall off the creature and land Prone. If the save is a critical failure, the triggering creature also takes 1d6 bludgeoning damage in addition to the normal damage for the fall.

Speed 50 feet

Melee Antlers +13 (deadly d8), Damage 2d6+7 piercing

Melee Hoof +13, Damage 2d4+7 bludgeoning

Furious Charge

The megaloceros Strides twice and makes a hoof Strike after either Stride. If the Strike hits, the megaloceros deals an additional 2d4 bludgeoning damage.

Pathfinder #176: Lost Mammoth ValleyOGL