Innate Spellcasting. The cackler's innate spellcasting ability is Charisma (spell save DC 11 , +3 to hit with spell attacks). The cackler can innately cast the following spells, requiring no material components:

At will: Fire Bolt. Casting Time (1 action), Range (120 ft), Target (A creature or object within range), Components (V, S), Duration (Instantaneous), Effect: You hurl a mote of fire at a creature or object within range. Make a ranged spell attack against the target. On a hit, the target takes 1d10 fire damage. A flammable object hit by this spell ignites if it isn’t being worn or carried.

1/day: Tasha's Hideous Laughter. Casting Time (1 action), Range (30 ft), Target (), Components (V, S, M (tiny tarts and a feather that is waved in the air)), Duration (Concentration, up to 1 minute), Effect: A creature of your choice that you can see within range perceives everything as hilariously funny and falls into fits of laughter if this spell affects it. The target must succeed on a Wisdom saving throw or fall prone, becoming incapacitated and unable to stand up for the duration. A creature with an Intelligence score of 4 or less isn’t affected. At the end of each of its turns, and each time it takes damage, the target can make another Wisdom saving throw. The target has advantage on the saving throw if it’s triggered by damage. On a success, the spell ends.

Last Laugh. When the cackler dies, it releases a dying laugh that scars the minds of other nearby creatures. Each creature within 10 feet of the cackler must succeed on a DC 11 Wisdom saving throw or take 2 (1d4) psychic damage.   Mimicry. The cackler can mimic any sounds it has heard, including voices. A creature that hears the sounds can tell they are imitations with a successful DC 11 Wisdom (Insight) check.