What’s 7 feet tall, covered in fur, can easily hide in the forest, and rip you apart with its four claws?
The Quadquatch
Hit Dice: 3
Armor Class: 6[13]
Attacks: 4 Claws (1d6), Bite (1d8)
Saving Throw: 14
Special: Stealthy
Move: 12
Alignment: Neutral
Challenge Level/XP: 4/120

This large four-armed humanoid lives primarily in wooded areas. Quadquatches are generally avoid contact with other species but males can become very hostile and territorial during mating season. Quadquatches have a habit of collecting shiny objects. Occasionally, valuable objects can be found in their nests. Some magic-users can craft invisibility cloaks or other magical garments related to stealth from a quadquatch’s hide.
Stealthy: There is a 3 in 6 chance that a quadquatch can surprise a party of adventurers. Additionally, there is a 2 in 6 chance that the creature cannot be tracked by any means magical or mundane.