Brute. A melee weapon deals one extra die of its damage when the bugbear hits with it (included in the attack).

Surprise Attack. If the bugbear surprises a creature and hits it with an attack during the first round of combat, the target takes an extra 7 (2d6) damage from the attack.

Guarded break

If the creature has not used Precise attack since the start of their last turn, their AC is increased by 2.

Infrequent attacks

The creature has disadvantage on attacks unless a said attack is affected by Precise attack. 

Morningstar. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 11 (2d8 + 2) piercing damage.

Javelin. Melee or Ranged Weapon Attack: +4 to hit, reach 5 ft. or range 30/120 ft., one target. Hit: 9 (2d6 + 2) piercing damage in melee or 5 (1d6 + 2) piercing damage at range.

Precise attack (Recharge 5-6)

 the creature gears up for a powerful strike. The next attack the creature makes deals an extra 2d6 damage, of the same type the attack deals.