Adult Mountain Stalker

Loose Skin. The stalker has resistance to slashing and bludgeoning damage because of its loose, thick skin.

Spellcasting. The Stalker is a second-level spellcaster. Its spellcasting ability is dexterity (spell save DC 12, +1 to hit with spell attacks). The Stalker has following Sorcerer spells prepared:

2nd level (4 slots): Blur, Blindness/Deafness

Shove. The Stalker makes a strength check against the target and kicks the target 10ft away, knocking them prone on landing.
Grab. A one-armed grapple that does not hinder the stalker's movement or actions.
Multi-Attack. Un-threatened, the stalker can Lash twice and Gut Punch once in its turn, but when a creature is within 5ft of the stalker, it can Gut Punch twice in its turn or Gut Punch once and Ice Breaker once.

Lash. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 57 (8d8 + 25) Slashing damage.
Gut Punch. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 55 (8d10 + 15) Bludgeoning damage. Make a Con 20 save, on a fail, drop speed by 20ft.
Glass Breaker. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 69 (10d12 + 9) Slashing damage. Increased crit range (20-19). Rib breaker: On a crit, lose all speed for your next two turns, and fall prone until your next turn. Make a medicine check on your turn(DC:19), on success, recover half your speed for that turn, on fail, wince and lose reaction for that turn. 

Throw. The Stalker makes a strength check against the target and throws the target 25ft in a direction of its choosing, knocking them prone on landing.

Shake. When hit by ranged piercing damage, make a dex save (DC: 18), on success, shake off the damage entirely.