Arcane Weasel

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

Arcane Attunement: The Arcane Weasel can sense the presence of magic within 30 feet of it. This functions similarly to the Detect Magic spell, but only as a passive awareness, not an actionable spell. The weasel knows the direction of any magical object or creature within range, but not the type or nature of the magic.

Magical Camouflage: The Arcane Weasel can blend with its surroundings by manipulating light and shadow around it. As an action, it can become invisible for 1 minute or until it attacks or casts a spell. It can use this ability once per short or long rest.

Bite. Melee Attack Roll: +5, reach 5 ft. Hit: 1 Piercing damage.

Ethereal Slip: (Once per long rest) Phases into the Ethereal Plane and moves through objects and creatures until the end of its next turn.