Antimagic Susceptibility. While the broom is in the area of an Antimagic Field it has the Incapacitated condition. When it is targeted by Dispel Magic, it must succeed on a Constitution saving throw against the caster's spell save DC or have the Unconscious condition for 1 minute.
False Appearance. As long as the broom is motionless and not flying, nothing distinguishes it from a normal broom.
Actions
Multiattack. Makes two Broomstick attacks.
Broomstick. Whacks a target with its handle.
Reactions
Animated Attack. Trigger: a creature takes hold of the broom while the broom is motionless. Response: the broom makes a Dexterity check opposed by the creature's Strength check. If the broom's total is higher, it flies free of the creature's grip and makes one melee attack against that creature with Advantage.