Ball Lightning

Flyby. The ball lightning does not provoke opportunity attacks when it flies out of an enemy's reach.

Grounded Lightning. The first on a turn the ball lightning touches the ground, it takes 11 (2d10) force damage

Illumination. The ball lightning sheds bright light in a 10-foot radius and dim light for an additional 10 feet.

Lightning Form. The ball lightning can move through a space as narrow as 1 inch wide without squeezing. A creature that touches the ball lightning or hits it with a melee attack while within 5 feet of it takes 6 (1d10) lightning damage.

Crackling Death. When the ball lightning dies, it explodes. Each creature within 20 feet of it must make a DC 15 Dexterity saving throw, taking 22 (4d8) lightning damage on a failed save, or half as much on a successful one. The explosion destroys the ball lighting.

Chain Lightning. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit:  22 (4d8) lightning damage, and lightning jumps to one creature of the ball lightning's choice within 30 feet of the target. That second target must succeed on a DC 15 Dexterity saving throw or take 11 (2d8) lightning damage. Then, if that creature fails it's save, the ball lightning chooses another creature within 30 feet of the second creature that has not been targeted by this attack yet. The new target must make a DC 15 Dexterity saving throw or take 11 (2d8) lightning damage. If that creature fails it's save, repeat the process of choosing new targets to make saves until either  a creature succeeds or all viable targets have been targeted.