Bigfoot

Aggressive. As a bonus action, the bigfoot can move up to its speed toward a hostile creature that it can see.

Keen Senses. The bigfoot has advantage on Wisdom (Perception) checks that rely on sight, hearing, or smell.

Multiattack. The bigfoot makes two slam attacks.

Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (1d10 + 5) bludgeoning damage. 

Small Tree/Large Rock. Ranged Weapon Attack: +7 to hit, range 15/30 ft., one target. Hit: 12 (2d6 + 5) bludgeoning damage.

Observation Awareness. When a Small or larger creature within 60 feet of it notices the bigfoot, it can use its reaction to turn awkwardly toward them and pose, becoming aware of the observer.