Belgor the Devourer

Amphibious: The Creature can breathe underwater and air.

Legendary Resistance (4/Day): If the dragon fails a saving throw, it can choose to succeed instead. 

Multiattack: The Dragon can use it's Frightful Presence. It then makes four attacks: one with it's bite, two with it's claws, and one with it's tail.

Bite: Melee weapon attack: +15 to hit, reach 10 ft., one target. Hit: (3d12 +9) piercing damage plus (3d10) acid damage.

Claw: Melee Weapon Attack: +15 to hit, reach 20 ft., one target. Hit: (3d8 + 9) slashing damage plus (3d4 + 9) acid damage. 

Tail: Melee Weapon Attack: +15 to hit, reach 30 ft., one target. Hit: (3d10 + 9) bludgeoning damage plus make a strength saving throw (DC 19) or be knocked prone. 

Frightful Presence: Each creature of the dragon's choice that is within 120 ft of the dragon and aware of it must succeed on a DC 19 wisdom saving throw or become frightened frightened for 1 minute. A creature can repeat the saving throw at the end of each of it's turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours. 

Acid Breath(Recharge 5-6): The dragon exhales acid in a 90 foot line that is 20 ft wide. Each creature in that line must make a DC 22 Dexterity saving throw, take (20d8) acid damage on a failed save, or half as much damage on a successful one. 

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Reaction Name. Enter the description for your action.

The dragon can take 5 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another's creature's turn. The dragon regains spent legendary actions at the start of it's turn. 

Detect: The dragon makes a Wisdom(Perception) Check.

Tail Attack: The Dragon make's a tail attack. 

Wing Attack(Costs 2 Actions): The dragon beats it's wings. Each creature within 20 ft of the dragon must succeed on a DC 23 Dexterity saving throw or take (3d12 + 9) bludgeoning damage and be knocked prone. The dragon can then fly up to half it's flying speed. 

Acid Breath(Costs 2 Actions): The dragon exhales acid in a 90 foot line that is 20 ft wide. Each creature in that line must make a DC 22 Dexterity saving throw, take (20d8) acid damage on a failed save, or half as much damage on a successful one. 

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Mythic Action Name (Costs # Actions). Enter the description for your mythic action.