Aetherling Beast

Ethereal Form. Aetherling Beasts can move through a space as narrow as 1 inch without squeezing.

Illumination. Aetherling Beasts emit a 5ft radius of dim light while conscious. 

Death Burst. When the Aetherling Beast drops to 0 hit points, all creatures within 15ft must make a DC 12 Charisma Saving throw or take 7(2d4+2) Force Damage and 7(2d4+2) Radiant Damage

Ethereal Jump. An Aetherling Beast can teleport up to 60ft as an action. This teleport can include a willing creature within 5ft. The Aetherling Beast can be on the Border-Ethereal or on the same Plane as the additional creature and still use allow them to Ethereal Jump with them. After teleporting, both the Aetherling and the willing creature are in the Border-Ethereal as per the Etherealness spell until the end of the Aetherling Beast's current turn. 

Ethereal Scratch. Melee Weapon Attack: +5 to hit, reach 5 ft., 1 target. Hit:  5(1d4 + 3) Force damage. This attack can hit creatures in the Border-Ethereal

Ether Shift. When the Aetherling Beast is hit with an attack it can move into the Border-Ethereal until the start of its next urn, negating all damage unless the attack can hit into the Border-Ethereal.