Your Strength score increases by 2, and your Dexterity score increases by 1.

Bugbears reach adulthood at age 16 and live up to 80 years.

Bugbears are between 6 and 8 feet tall and weigh between 250 and 350 pounds. Your size is Medium.

Your base walking speed is 30 feet.

You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can’t discern color in darkness, only shades of gray.

When you make a melee attack on your turn, your reach for it is 5 feet greater than normal.

You count as one size larger when determining your carrying capacity and the weight you can push, drag, or lift.

You are proficient in the Stealth skill.

If you surprise a creature and hit it with an attack on your first turn in combat, the attack deals an extra 2d6 damage to it. You can use this trait only once per combat.

You can speak, read, and write Common and Goblin.

Amorphous

 The horror can move through any opening at least 1 inch wide without squeezing

You no longer require sleep. You still will need to trance for about 6 hours in order to replenish most of your character features. 

Due to your nature your form requiring constant meditation in order to maintain your remembered form. Otherwise you risk turning into a fungus pile.

You can cast find familiar, and gain a custom summon, your own skeleton. Your own skeleton uses the state block from the skeleton in the Monster Manual.