Cold Burn

Harden / Liquify. The Cold Burn can cool down and heat up at will, freezing itself to make sharp points ,or heat itself up to be burning to the touch.

Slash. Melee Weapon Attack: +5 to hit, reach 15 ft., 2 targets. Hit: 20 (3d6 + 2) slashing damage. (1d4 + 1) cold damage. (1d4 + 1) acid damage. 

Slap. Melee Weapon Attack: +5 to hit, reach 15 ft., 1 target. Hit:    (2d6 + 1) bludgeoning damage. (1d12 + 2) fire damage. (1d4 + 1) acid damage.

Bite. Melee Weapon Attack: +5 to hit, reach 15 ft., 1 target. Hit: 25 (3d8 + 3) piercing damage. (1d4 + 1) cold damage. (2d4 + 1) acid damage. The creature must make a DC 14 Dexterity saving throw, the creature takes the same amount of damage it took before the save on a successful saving throw. and is restrained and takes 10 (3d4 + 3) acid damage on the Cold Burn's turn on a failed save. On the creatures turn if it failed the saving throw, can choose to make a DC 14 Strength saving throw, and if it succeeds, the creature is no longer restrained by the Cold Burn. and if it fails the creature continues to be restrained by the Cold Burn.

Swallow. The creature must be restrained by the Cold Burn's bite, the creature must make a DC 14 Dexterity saving throw.

On a successful save, the creature can choose to make a saving throw to get out of the Cold Burn's mouth. on a successful save the creature is no longer restrained by the Cold Burn. on a failed save the creature is still restrained by the Cold Burn, but is not swallowed.

On a failed save, the Cold Burn swallows the creature, and the creature takes 10 (3d6) acid damage and is swallowed. The swallowed creature can't breathe, is restrained, and takes 21 (6d6) acid damage at the start of each of the Cold Burn's turns. When the Cold Burn moves, the swallowed creature moves with it.

An swallowed creature can try to escape by taking an action to make a DC 12 Strength check. On a success, the creature escapes and enters a space of its choice within 5 feet of the Cold Burn.