Shapechanger: The imp can use its
Action to
Polymorph into a beast form that resembles a rat (speed 20 ft.), a raven (20 ft., fly 60 ft.), or a
Spider (20 ft., climb 20 ft.), or back into its true form. Its
Statistics are the same in each form, except for the speed changes noted. Any
Equipment it is wearing or carrying isn't
Transformed. It reverts to its true form if it dies.
Devil's Sight:
Magical Darkness doesn't impede the imp's
Darkvision.
Magic Resistance: The imp has advantage on
Saving Throws against
Spells and other
Magical Effects.
Sting (Bite in Beast Form): Melee Weapon Attack: +5 to hit, reach 5 ft ., one target. Hit: 5 (1d4 + 3) piercing damage, and the target must make on a DC 11
Constitution saving throw, taking 10 (3d6) poison damage on a failed save, or half as much damage on a successful one.
Invisibility: The imp magically turns
Invisible until it
Attacks, or until its
Concentration ends (as if concentrating on a spell). Any
Equipment the imp wears or carries is
Invisible with it.