Imp Trickster

Tiny Fiend (Devil), Lawful Evil

STR
6 (-2)
DEX
17 (+3)
CON
13 (+1)
INT
11 (+0)
WIS
12 (+1)
CHA
14 (+2)
Magic Resistance.

The imp has Advantage on saving throws against spells and other magical effects.

Actions

Sting.

Melee Attack Roll: +5, reach 5 ft. Hit: 1d6 + 3 Piercing damage plus 2d6 Poison damage.

Invisibility.

The imp has the Invisible condition for 1 minute. This effect ends early immediately after the imp makes an attack roll or deals damage, or if the imp has the Incapacitated condition.

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 game statistics are the same in each form, except for its Speed. Any equipment it is wearing or carrying isn't transformed.

Find this creature in the encounter builder

Imp Trickster

Source: Stranger Things: Welcome to the Hellfire Club - Licenses and attribution