Aberrant Master. An aberrant underling is the minion of an Aboleth, Beholder, or Mind Flayer (DM’s choice), which determines the following trait:
Amphibious (Aboleth Only). The underling can breathe air and water, but takes 6 (1d12) Acid damage at the end of every 10 minutes unless moisture is applied to its skin before those minutes have passed.
Infected Mind (Mind Flayer Only). The underling has Advantage on Intelligence, Wisdom, and Charisma D20 Tests, but dies if it has the Incapacitated condition.
Paranoia (Beholder Only). The underling has Advantage on Initiative rolls, but has Disadvantage on Wisdom-based D20 Tests.

Vassalic Conditioning. The underling has Immunity to the Charmed and Frightened conditions unless they are from effects created by its aberrant master.

Dagger. Melee or Ranged Attack Roll: +4, reach 5 ft. or range 20/60 ft. Hit: 4 (1d4 + 2) Piercing damage plus 2 (1d4) Psychic damage.

Mind Rot (Recharge 6). Intelligence Saving Throw: DC 11, one creature the underling can see within 30 feet. Failure: 8 (2d6 + 1) Psychic damage, and the target has Disadvantage on the next D20 Test it makes before the end of its next turn. Success: Half damage only.