Butterfly Weasel

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

fey ancestory: the weasel has advantage on saving throws against being charmed and magic cant put the weasel to sleep

variant familiar: the weasel can serve another creature as a familiar, forming a magic telepathic bond with that willing companion. While the two are bonded, the companion can sense what the weasel senses as long as they are within 1 mile of each other. While the weasel is within 10 feet of its companion, the companion shares the weasel's magic resistance trait. At any time and for any reason, the weasel can end its service as a familiar, ending the telepathic bond.  

evasion: if the weasel is subjected to an effect that allows it to make a dexterity saving throw to take only half damage, the weasel instead takes no damage if it succeeds and half damage if it fails.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 5 (1d4 + 3) piercing damage.

claws. melee weapon attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d6+3) slashing damage.

Twister. the weasel can attempt to trip an opponent sized medium or bigger by running in loops around its ankles. the target must make a dexterity saving throw DC 13 or be knocked prone.

Shimmering shield: as a reaction the weasel can cast a shimmering shield around it or a creature within 5 feet of it. the shield grants the creature a +3 to their AC and is considered magical for the purpose of effects. Creatures behind the shield gain advantage on saving throws against spells that require a charisma save. The shield lasts for one round. the weasel can cast this shield 4/day.