Skills. Athletics +8, Perception +4, Stealth +8

Legendary Spell Resistance (3/day). If the abyssal vermillion fails a saving throw against a spell, it can choose to succeed instead. When under the effects of a spell that has no saving throw, the abyssal vermillion may expend two uses of legendary resistane to end the spell.

Magic Weapons. The abyssal vermillion's weapon attacks are magical.

Pounce. The the abyssal vermillion moves at least 20ft straight toward a creature and then hits it with a claw attack on the same turn, the target must succeed on a DC 16 Strength saving throw or be knocked prone. The the target is knocked prone, the abyssal vermillion can make an attack with its bite against it as a bonus action.

Spell Reflecting Hide. The abyssal vermillion gains advantage on all saving throws against spells. If the abyssal vermillion succeeds at a saving throw against a spell or is missed by a spell attack, and the spell targets only the abyssal vermillion, the spell is stored within the abyssal vermillions hide. The abyssal vermillion may later release this energy (see legendary actions); it may only store one spell at a time, however.

Multiattack. The abyssal vermillion makes three attacks: one with its bite, one with its claw, and one with its tail.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft, one target. Hit 20 (4d8+2) piercing damage, and the target is grappled (escape DC 16). Until this grapple ends, the target is restrained and the abyssal vermillion can't bite another target.

Claw. Melee Weapon Attack: +8 to hit, reach 10 ft, one target. Hit 14 (2d8 + 5) slashing damage.

Tail. +7 to hit, reach 15 ft, one target. Hit 12 (2d8 + 3) bludgeoning damage. If the target is a creature, it must succeed on a DC 16 Strength saving throw or be knocked prone and pushed 10 ft in a direction of the abyssal vermillion's choosing.

The abyssal vermillion can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creatures turn. The abyssal vermillion regains spent ledendary actions at the start of its turn.

Deadly Speed. The abssal vermillion moves its speed and makes a claw attack. This movement doesn't provoke an attack of opportunity. 

Flurry of Claws (Costs 2 actions). The abyssal vermillion unleashes a flurry of claw attacks. Each creature within 10ft of the abyssal vermillion must succeed on a DC 14 Dexterity saving throw or take 14 (2d8 + 5) slashing damage and be knocked prone.

Lave-Oozing Hide. Until the start of the vermillion's next turn, any creature that touches the vermillion of hits it with a melee attack while within 5ft of it takes 7 (2d6) fire damage.

Release Stored Spell. The abyssal vermillion releases a spell it has stored with spell-reflecting hide. The stored spell targets a creature within the range of the spell, as if the abyssal vermillion was the caster. The stored spell uses the spell slot level, save DC, attack bonus, and spellcasting ability of the original caster.

Tail Attack. The abssal vermillion makes a tail attack.