bawler

Skin of Fire. Whenever a creature makes an unarmed melee attack or grapples the Bawler, they must make a dc14 constitution saving throw, or take 1d4 fire damage.

Spellcasting. The Bawler is a 4th-level spellcaster (spell save DC 11, +3 to hit with spell attacks). The Bawler has following spells prepared:
Cantrips (at will): [Fire Bolt], [Create Bonfire] 
4th level (2 slots): [Fireball], [Fire Shield] 

Rolling Flames. Bawler can choose to curl up into a ball, and roll around, doubling it's movement speed, but not allowing for it to make any attacks that turn.

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., 1 target. Hit: 7 (2d4 + 3) [piercing] damage. 

Breath Weapon. RangedWeapon Attack: +2 to hit, range 10/25 ft., 4 target. Hit: 15 (3d6 + 6) [fire] damage.

1 bonus action per turn.

Burrow. It can burrow into the ground, causing it to be invulnerable to all melee attacks, treat this as a concentration spell, it lasts until his next turn, and when activated, automatically ends his turn.

Multiattack. The Bawler can choose to make 2 bite attacks in a row as a bonus action, this can be used once per short rest.

Gluttony. When any creature makes a ranged spell attack that has a physical object at the Bawler, it can spend a reaction to consume the spell, and dealing half that damage to the next person it bites..