Black Iron Boar

Charge. If the boar moves at least 20 feet straight toward a target and then hits it with a tusk attack on the same turn, the target takes an extra 3 (1d6) slashing damage. If the target is a creature, it must succeed on a DC 11 Strength saving throw or be knocked prone.

Relentless (Recharges after a Short or Long Rest). If the boar takes 7 damage or less that would reduce it to 0 hit points, it is reduced to 1 hit point instead.

Barbed Hide. At the start of each of its turns, the creature deals (4d10) piercing damage to any creature grappling it.

Iron Scent. The creature can pinpoint, by scent, the location of ferrous metal within 30 feet of it.

Magic Resistance. The creature has advantage on saving throws against spells and other magical effects.

Reflective Carapace. Any time the creature is targeted by a magic missile spell, a line spell, or a spell that requires a ranged attack roll, roll a d6. On a 1 to 5, the creature is unaffected. On a 6, the creature is unaffected, and the effect is reflected back at the caster as though it originated from the creature, turning the caster into the target.

Treasure Sense. The creature can pinpoint, by scent, the location of precious metals and stones, such as coins and gems, within 60 feet of it

Tunneler. The creature can burrow through solid rock at half its burrow speed and leaves a 10-foot-diameter tunnel in its wake.

Tusk. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) slashing damage.

Enlarge (Recharges after a Short or Long Rest). For 1 minute, the creature magically increases in size, along with anything it is wearing or carrying. While enlarged, the creature is Large, doubles its damage dice on Strength-based weapon attacks (included in the attacks), and makes Strength checks and Strength saving throws with advantage. If the creature lacks the room to become Large, it attains the maximum size possible in the space available.

1. Chomp (Costs 2 Actions). The creature makes one bite attack or uses its Swallow.