Telepathy. The Voidling can magically transmit simple messages and images to any creature within 120 feet of it that can understand a language.

Superior Darkvision. The voidling has Darkvision of 120 feet. 

Amorphous. The voidling can move through a space as narrow as 1 inch wide without squeezing.

Multiattack. The Voidling makes three attacks: one with its engulf and two with its tentacles.

Engulf. The Voidling moves up to its speed. While doing so, it can enter Large or smaller creatures' spaces. Whenever the Voidling enters a creature's space, the creature must make a DC 12 Dexterity saving throw.

On a successful save, the creature can choose to be pushed 5 feet back or to the side of the Voidling. A creature that chooses not to be pushed suffers the consequences of a failed saving throw.

On a failed save, the Voidling enters the creature's space, and the creature takes 10 (3d6) necrotic damage and is engulfed. The engulfed creature can't breathe, is restrained.

An engulfed creature can try to escape by taking an action to make a DC 12 Strength check. On a success, the creature escapes and enters a space of its choice within 5 feet of the cube.

Tentacle. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 7 (1d8 + 3) bludgeoning damage plus 4 (1d8) piercing damage. If the target is Medium or smaller, it is grappled (escape DC 13) and restrained until the grapple ends. The otyugh has two tentacles, each of which can grapple one target.

Tentacle Slam. The voidling slams creatures grappled by it into each other or a solid surface. Each creature must succeed on a DC 14 Constitution saving throw or take 10 (2d6 + 3) bludgeoning damage and be stunned until the end of the otyugh's next turn. On a successful save, the target takes half the bludgeoning damage and isn't stunned.