Electrolocation. Using electrolocation, the Zanathor can sense anything, living or non-living, in a 65 feet radius(e.g. invisibility, in darkness)

Lightning Armour. When the Zanathor is hit up to 3 times using a nonmagical attack, the attacker takes 1d6 damage

Thunder Spear. +2 to hit. The Zanathor forms a thunder spear in it's hands, which it then throws towards a target, dealing (1d12+2) piercing damage. 

Static Grab. +3 to hit. Zanathor dashes up to 15 feet. While dashing, if a character is in it's dash range, it grabs and lifts them up in the air and shocking them, dealing(1d10+3) lightning damage.

Voltage Overload. The Zanathor explodes itself in a 50 feet radius which deals(3d10) damage and paralyses anything hit by it for 4 minutes. If it explodes in Electric Domain, deal an extra 1d8 damage and paralyses anything in it's radius for 8 minutes instead, but kills itself.

Electro Beam. Zanathor puts it's two hands together and pushes pure lightning out of it's hands in front of it, dealing(2d10) lightning damage and damages anyone nearby in a 10 feet radius, dealing 1d8 damage.

Electric Domain. When the Zanathor is at 50% HP, it casts a giant domain around it, that is 100 feet in length, width and height. It lasts for 15 turns or ends when the battle is over. The domain gives it advantage on every attack roll and saving throw and can be stacked on top of it's modifiers. It also paralyses everyone in the domain for 1 turn every 3 turns.

Thunderstorm Anger. If there is a thunderstorm, the Zanathor gains a +5 in it's AC, a +3 on all of it's score, a +20 on it's hitpoint modifier and has increased speed and flight but slowly loses it's health(2d8 damage)