Coilspire Wyrm

Traits

• Legendary Resistance (3/Day). If the creature fails a saving throw, it can choose to succeed instead.
• Magic Resistance. The creature has advantage on saving throws against spells and other magical effects.
• Static Nimbus. The wyrm is sheathed in crawling static electricity. A creature that touches the wyrm or hits it with a melee attack while within 5 feet of it takes 7 (2d6) lightning damage. While the wyrm is in contact with metal or standing in water, this damage increases to 10 (3d6).

Innate Spellcasting

Its spellcasting ability is Charisma (spell save DC 17, +9 to hit with spell attacks).

• Cantrips. Call Lightning, Gust of Wind

Actions

• Bite. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 2d10 + 6 piercing damage. Melee Weapon Attack. The wyrm's jaws crackle with static as they close. On a hit, the target must succeed on a DC 17 Constitution saving throw or be unable to take reactions until the start of its next turn as its muscles lock.
• Claw. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 2d4 + 6 slashing damage. Melee Weapon Attack. The wyrm rakes with forelimb talons that spark against stone.
• Tail. Melee Weapon Attack: +11 to hit, reach 15 ft., one target. Hit: 2d8 + 6 bludgeoning damage. Melee Weapon Attack. The wyrm lashes with its long, whip-coiled tail. If the target is a creature, it must succeed on a DC 20 Strength saving throw or be pushed up to 10 feet away and knocked prone.
• Lightning Breath (Recharge 5-6). Hit: 12d10 lightning damage. The wyrm exhales a roaring bolt of lightning in a 90-foot line that is 5 feet wide. Each creature in that line must make a DC 19 Dexterity saving throw, taking 66 (12d10) lightning damage on a failed save, or half as much on a successful one. A creature that fails is also deafened until the end of its next turn.

Bonus Actions

• Skyward Coil. The wyrm surges up to half its flying speed without provoking opportunity attacks and crackling thunder rolls out behind it. The first creature it flies within 5 feet of during this movement must succeed on a DC 17 Constitution saving throw or be deafened until the end of the wyrm's next turn.

Reactions

• Grounding Lash. The wyrm whips its tail at the attacker, who must succeed on a DC 20 Dexterity saving throw or take 14 (2d8 + 5) bludgeoning damage plus 7 (2d6) lightning damage and be knocked prone as the charge earths through them.

Legendary Actions

• Detect. The wyrm makes a Wisdom (Perception) check.
• Tail Attack. The wyrm makes one Tail attack.
• Wing Attack. The wyrm beats its storm-charged wings. Each creature within 15 feet must succeed on a DC 19 Dexterity saving throw or take 13 (2d6 + 6) bludgeoning damage and be knocked prone. The wyrm can then fly up to half its flying speed.