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

Pack Tactics. The wolf has advantage on an attack roll against a creature if at least one of the wolf's allies is within 5 feet of the creature and the ally isn't incapacitated.

Shadow replacement. The wolf can hide in any flora shadow. It can also hide in the shadows of creatures may they be on his good side. The shadow of the creature becomes the shape of the wolf.

Intimidate. When first seeing the Wolf, creatures that are large or smaller will have to make a DC 15 Con. saving throw or will be frightened untill the wolf drops below half hitpoints. 

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 12 (2d8 + 4) piercing damage. If the target is a creature, it must succeed on a DC 13 Strength saving throw or be knocked prone.

Shadow sneak. 1 time per 5 turns. Hit: 16 (3d8 + 3) piercing damage. Yuki can go into any flora shadow and exits within 80 feet out of another to flank. if it comes out within 10 ft of a creature, it can attack with advantage, but will move within 5 feet of the creature. 

Detect Evil and Good. (once per short rest) For the duration, you know if there is an aberration, celestial, elemental, fey, fiend, or undead within 30 feet of you, as well as where the creature is located. Similarly, you know if there is a place or object within 30 feet of you that has been magically consecrated or desecrated.

The spell can penetrate most barriers, but it is blocked by 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt.