Asteria

Keen Hearing and Smell. Asteria has advantage on Wisdom (Perception) checks that rely on hearing or smell.

Shadow Stealth. While in dim light or darkness, Asteria can take the Hide action as a bonus action. Her stealth bonus is also improved to +6

Shapechanger. Asteria can use its action to polymorph into a fiendish beast form that resembles a kitten, or back into her larger, more terrifying form.

Magic Resistance. Asteria has advantage on saving throws against spells and other magical effects.

Pounce. If Asteria moves at least 20 feet straight toward a creature and then hits it with a claw attack on the same turn, that target must succeed on a DC 12 Strength saving throw or be knocked prone. If the target is prone, the Asteria can make one bite attack against it as a bonus action.

Shadow Blend 

While in dim light or darkness, Asteria becomes invisible, along with anything she is wearing or carrying. The invisibility lasts until she uses a bonus action to end it or until she attacks, is in bright light, or is invisible.

Incorporeal Movement

Asteria can move through other creatures and objects as if they were difficult terrain. She takes 5 (1d10) force damage if she ends her turn inside an object.

Shadow Jump

As a bonus action, Asteria can teleport up to 50 feet to an unoccupied space she can see. Both the space she teleports from and the space she teleports to must be in dim light or darkness. She can use this ability between the attacks of another action she takes.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) piercing damage.

Claw. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 4 (1d4 + 2) slashing damage.

Shadow Stealth. While in dim light or darkness, Asteria can take the Hide action as a bonus action.