Armored Tusk Troll

Keen Smell. The troll has advantage on Wisdom (perception) checks that rely on smell.

Regeneration. The troll regains 10 hit points at the start of its turn. If the troll takes acid or fire damage, this trait doesn't function at the start of the troll's next turn. The troll dies only if it starts its turn with 0 hit points and doesn't regenerate.

Multiattack. The troll makes five attacks: one with its tusk gore and four times with its claws. If two or more claws hit the same target, the troll rends the target, dealing an extra 2d6 slashing damage.

Gore. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 22 (3d8 + 6) piercing damage.

Claw. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 16 (3d6 + 6) slashing damage.

Trampling Charge. If the Tusk Troll moves at least 20 feet straight toward a target and then hits with a gore attack on the same turn, that target must succeed on a DC 18 Strength saving throw or be knocked prone. 

Aggressive. As a bonus action, the Tusk Troll can move up to its speed toward a hostile creature that it can see.