Magmin

The monster explodes .
Dexterity Saving Throw: DC , each in a -foot Emanation originating from the monster.
Failure: damage.
Success: Half damage.

. . If the target is a creature or a flammable object that isn't being worn or carried, it starts burning.

The monster sets itself ablaze or extinguishes its flames. While ablaze, the monster sheds Bright Light in a 10-foot radius and Dim Light for an additional 10 feet.