Multiattack

The will-o'-wisp makes two Shock attacks.

Shock

Melee Spell Attack: +5 to hit, reach 5 ft., one target. _Hit:_ 10 (2d6+3) lightning damage.

Invisibility

The will-o'-wisp and its light magically become invisible until it attacks or uses its Beckon, or until its concentration ends (as if concentrating on a spell).