Bugbear Assassin

Assassinate. During its first turn, the bugbear has advantage on attack rolls against any creature that hasn't taken a turn. Any hit the bugbear scores against a surprised creature is a critical hit.

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

Evasion. If the bugbear is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, the bugbear instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.

Sneak Attack (1/Turn). The bugbear deals an extra 14 (4d6) damage when it hits a target with a weapon attack and has advantage on the attack roll, or when the target is within 5 feet of an ally of the bugbear that isn't incapacitated and the bugbear doesn't have disadvantage on the attack roll.

Scimitar. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage and the target must make a DC 15 Constitution saving throw, taking 24 (7d6) poison damage on a failed save, or half as much damage on a successful one.

Garrote. Melee Weapon Attack: +7 to hit, reach 5 ft., one Medium or Small creature against which the bugbear has advantage on the attack roll. Hit: 9 (2d4 + 4) bludgeoning damage, and the target is grappled (escape DC 12). Until the grapple ends, the target can't breathe and takes 14 (4d4 + 4) bludgeoning damage at the start of each of the bugbear's turns. The bugbear can't make weapon attacks while grappling a creature in this way.

Javelin. Melee or Ranged Weapon Attack: +7 to hit, reach 5 ft. or range 30/120 ft., one target. Hit: 11 (2d6 + 4) piercing damage in melee or 7 (1d6 + 4) piercing damage at range.

Cunning Action. The bugbear can take the Dash, Disengage, or Hide action as a bonus action on each of its turns.