Beast Master Ferret

Keen Hearing, Sight and Smell. The ferret has advantage on Wisdom (Perception) checks that rely on hearing, sight or smell.

Coordinated Attack: Beginning at 5th level, you and your animal companion form a more potent fighting team. When you use the Attack action on your turn, if your companion can see you, it can use its reaction to make a melee attack.

Ignorance Is Bliss. The ferret is blind to danger and has advantage on all saving throws against being frightened.

Which Way Did He Go... Ferrets move so erratically, it's hard to pinpoint which direction it will move next. Any creature of size small or larger has disadvantage on attack rolls against the ferret. An attacker is immune to this effect if it doesn't rely on sight, as with blindsight. 

Short Attention Span. On a Nat 1, the ferret forgets it's assignment and takes one of the following instead (d4):

• 1. The ferret, seeing a foot and thinking it's playtime, takes the Bite action (no modifier) on the ankle of the nearest target.
• 2. The ferret dooks (This sound is similar to a chicken clucking, and it indicates your ferret is happy or excited.) and then proceeds with your desired action to the best of it's ability. You gain 1d6 that can be added to any one ability check, attack roll, or saving throw (bardic inspiration). 
• 3. The ferret is distracted by the nearest shiny object and moves half it's movement towards it (object at DMs discretion)
• 4. The ferret does a weasel war dance. All friendly creatures in a 15 foot radius gain 1d6 temp HP. 

Multiattack. The ferret makes two attacks: one with its bite and one with its claws.

Storm of Claws and Fangs. Your companion can use its action to make a melee attack against each creature of its choice within 5 feet of it, with a separate attack roll for each target.

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) piercing damage. (Roll with advantage when ferret is attached to the creature). 

Claws. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 7 (2d4 + 2) slashing damage. (Roll with advantage when ferret is attached to the creature). 

Shimmy: The ferret attempts to penetrate the clothes of an individual (strength DC 14). On a success, the ferret may use the Claw attack twice and stays nestled in the garments of the individual. On a fail, take the Claw attack. 

Cat Snake. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 6 (1d8 + 2) bludgeoning damage, and the target is grappled (strength DC 14). Until this grapple ends, the creature is restrained, and the ferret can't harm another target. The ferret wraps around the creatures neck, cutting off air supply, this will half movement speed (increasing by -5 on each failed save). The creature may not speak or use any of its actions until the ferret is removed from the creatures neck or the creature breaks the grapple. 

Nimble Escape. The trained pet ferret can take the Disengage or Hide action as a Bonus Action on each of its turns.

Slippery Little Devil. When a creature successfully grapples the ferret, the ferret makes a Bite  attack (see Actions Bite.). If the attack is successful the trained pet ferret is no longer grappled.