Behemoth

Siege Monster. The Behemoth deals double damage to objects and structures.

Keen Sight and Smell. The Behemoth has advantage on Wisdom (Perception) checks that rely on sight smell.

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

Titanic Wrath. Any damage the Behemoth deals ignores resistance, treats immunity as resistance and are considered magical.

Standing Leap. The Behemoth's long jump is up to 80 feet long and its high jump is up to 60 feet high, with or without a running start.

Legendary Resistance (3/Day). If the Behemoth fails a saving throw, it can choose to succeed instead.

Multiattack. The behemoth makes two claw attacks and one wild horn attack.

Claw. Melee Weapon Attack: +15 to hit, reach 5 ft., one creature. Hit: 56 (8d10 + 8) Slashing damage.

Wild Horn. Melee Weapon Attack: +15 to hit, reach 15 ft. one creature. Hit: 70 (10d12 + 10) Piercing damage.

Tail Sweep. Melee Weapon Attack: +15 to hit, reach 15ft. Hit: 44 (8d10 + 8) bludgeoning damage. Each creature within 10 feet of the behemoth must succeed on a DC 20 Dexterity saving throw or be knocked prone.

Flame Armor. A red, fiery aura covers the Behemoth. The effects of this action last for 1 minute. Anytime creatures attacking with physical weapons, non-magical weapons or unarmed strikes successfully strike the Behemoth, the attacking creature(s) takes 58 (8d10 + 10) Fire damage.

Strengthening Howl. The Behemoth unleashes a thunderous howl that empowers it's attacks. For the next minute, the Behemoth's attacks are made with advantage.

Meteor. The Behemoth summons a rock that drops from the sky. Hostile creatures within 50 ft. diameter sphere of the meteor when it collides with the ground takes 91 (13d12) Bludgeoning damage and 84 (12d10) Fire damage. Creatures hit must then make a DC 25 Strength or Dexterity saving throw (their choice) or be knocked prone on a failure.

The Behemoth can take 3 legendary actions, choosing from the option below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The Behemoth regains spent legendary actions at the start of its turn.

Ecliptic Meteor (Costs 3 Actions). The Behemoth rears onto its hind legs and roars to the sky. The sky becomes cloaked in smoke, ash and fire as a massive meteor descends upon the ground. Every creature other than the behemoth (and a number of creatures of its choice up to its Proficiency Bonus ) takes 220 (20d20) Bludgeoning damage and 220 (20d20) Fire damage.