Amphibious. The zodgilla can breathe air and water.

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

Energy Absorption. When the zodgilla is hit with elemental damage (that isn't cold), roll a d6. On a 1-5 the zodgilla takes half damage. On a 6, the zodgilla is unaffected. If the zodgilla is hit with lightning damage, it takes no damage and regains hit points equal to the damage of the attack. It's Bluefire is recharged. 

Multiattack. The zodgilla can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws.

Frightful Presence. Each creature of the zodgilla's choice that is within 120 feet of the zodgilla and aware of it must succeed on a DC 27 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its 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 zodgilla's Frightful Presence for the next 24 hours.

Bite. Melee Weapon Attack: +18 to hit, reach 10 ft., one target. Hit: 20 (3d10 + 10) piercing damage. If the target is a creature, it is grappled (escape DC 20). Until this grapple ends, the target is restrained, and the zodgilla can't bite another target.

Claw. Melee Weapon Attack: +18 to hit, reach 10 ft., one target. Hit: 29 (4d12 + 10) slashing damage.

Fire Breath (Recharge 4-6). The zodgilla exhales fire in a 90-foot cone. Each creature in that area must make a DC 25 Dexterity saving throw, taking 78 (14d10) fire damage on a failed save, or half as much damage on a successful one.

Bluefire (Recharge 6). The Zodgilla's fins crackle with blue energy, and exhales a column of blue fire, forming a line 150 feet long and 10 feet wide that shoots out in a direction you choose. Each creature in the line must make a DC 25 Dexterity saving throw. On a failed save, the creature takes 4d6 lightning damage and 4d6 fire damage, or half as much damage on a successful one. If this damage reduces the target to 0 hit points, it is disintegrated. The bluefire ignites flammable objects in the area that aren't being worn or carried.

The zodgilla can take 3 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 creature's turn. The zodgilla regains spent legendary actions at the start of its turn.

Attack. The zodgilla makes one claw or 

Move. The zodgilla moves up to half its speed.

Mighty Tail (Costs 2 Actions). Melee Weapon Attack: +18 to hit, reach 20 ft., one target. Hit: 25 (2d8 + 10) bludgeoning damage. If the target is a creature and is size huge to gargantuan, it must succeed on a DC 20 Strength saving throw or be grappled, if the creature is size tiny to large, it must mas a DC 20 Dexterity saving throw or takes 4d10 (plus a d10 for each size lower than large) bludgeoning damage and can be shoved up to 20 feet in any direction.