Sense Discharge. The lizard automatically knows the direction and distance to any creature that takes or deals lightning damage within 500 feet of it.

Shocker Lizard Packs.If two or more shocker lizards are in close proximity, they amplify each other’s lightning discharges. When a shocker lizard uses Lethal Shock, the damage increases by 9 (2d8) for every other shocker lizard within 20 feet of it, to a maximum of 36 (8d8) additional damage. Additionally, if at least three shocker lizards are within 20 feet of each other, Lethal Shock’s radius increases to 20 feet. However, once a shocker lizard uses Lethal Shock while within 20 feet of other shocker lizards, all shocker lizards within range must recharge Lethal Shock before they can use it again.

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d4 + 2) piercing damage. 

Debilitating Shock. Melee Spell Attack: +4 to hit, reach 5 ft., one target. Hit: If the target is a creature that has less than 10 hit points, it is knocked unconscious for 1 minute, or until it takes damage or another creature takes an action to shake it awake.

Lethal Shock (Recharges after a Short or Long Rest). The lizard discharges a lethal amount of lightning in a sphere centered on its tiny body, out to a radius of 10 feet from it. Each creature in the area must make a DC 12 Dexterity saving throw or take 9 (2d8) lightning damage.
Creatures made of (or wearing) metal have Disvantage on the save roll.