Magic Resistance.

The derro has advantage on saving throws against spells and other magical effects.

Sunlight Sensitivity.

While in sunlight, the derro has disadvantage on attack rolls.

Actions

Chaos Blast.

Melee or Ranged Spell Attack: +3 to hit, reach 5 ft. or range 60 ft., one target. Hit: 10 (3d6) damage. Roll a d4 to determine the damage type: 1, acid; 2, cold; 3, fire; 4, lightning.

Force Burst (Recharge 4–6).

Raw arcane magic bursts out from the derro. Each creature within 10 feet of it must make a DC 11 Strength saving throw. On a failed save, the creature takes 7 (2d6) force damage and has the prone condition. On a successful save, the creature takes half as much damage only.

Spellcasting.

The derro casts one of the following spells, using Charisma as the spellcasting ability (spell save DC 11):

At will: Message, Prestidigitation
1/day: Charm Person

Derro Apprentice