Armor Class 13
Hit Points 21 (6d4 + 6)
Speed 20 ft., fly 40 ft.
Skills Deception +4, Insight +3, Stealth +5
Damage Resistances cold
Damage Immunities fire, poison
Condition Immunities poisoned
Senses Darkvision 120 ft. (unimpeded by magical {@variantrule Darkness|XPHB}), passive Perception 11
Languages Common, Infernal
Challenge 1
Magic Resistance. The imp has Advantage on saving throws against spells and other magical effects.
Sting. m +5, reach 5 ft. Hit: 6 (1d6 + 3) Piercing damage plus 7 (2d6) Poison damage.
Shape-Shift. The imp shape-shifts to resemble a rat (Speed 20 ft.), a raven (20 ft., Fly 60 ft.), or a spider (20 ft., Climb 20 ft.), or it returns to its true form. Its statistics are the same in each form, except for its Speed. Any equipment it is wearing or carrying isn't transformed.
Monster Manual (2024), p. 177