Here's another by Chris Scaturo, a 5e conversion of the Dark Creeper.
Small Humanoid (underdark) , NE
Armor Class 16 (Rag Armor +2, Dex +4)
Hit Points 13 (3d6+3)
Speed 25 ft.
Skills Stealth +7, Sleight of Hand +7
Senses Darkvision 60 ft (see below)., passive Perception 11
Damage Vulnerabilities Sunlight (see below)
Damage Resistances Resistance
Damage Immunities Immunity
Condition Immunities Immunity
Challenge 1 (200 XP)
Superior Dark Vision. Dark Creepers can see in magical darkness out to 30’.
Sunlight Vulnerability. Dark Creepers have disadvantage on all attack rolls, saving throws, and ability checks when in direct sunlight.
Sneak Attack:. If the Dark Creeper has advantages on its attack the target takes an extra 7 (2d6) damage from the attack on one attack per round.
Dagger. Melee (or ranged) Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d4+4) piercing damage.
Cunning Action: You can take a bonus action on each of your turns in combat. This action can be used only to take the Dash, Disengage, or Hide action.
Extinguish Flame: As a bonus action, Dark Creepers can extinguish any mundane light source or magical light created by a 1st level spell or cantrip
Drow Dagger: One Dark Creeper possesses a Drow Dagger. The dagger is a +1 weapon when used underground and can cast WEB once per day as a 2nd level spell.
Casting Time: 1 action
Range: 60 feet
Components: V, S, M (a bit o f spiderweb)
Duration: Concentration, up to 1 hour
You conjure a m ass of thick, sticky webbing at a point of your choice within range. The w ebs fill a 20-foot cube
from that point for the duration. The w ebs are difficult terrain and lightly obscure their area. If the w ebs aren’t anchored between two solid m asses (such as walls or trees) or layered across a floor, wall, or ceiling, the conjured web collapses on itself, and the
spell ends at the start of your next turn. W ebs layered over a flat surface have a depth of 5 feet.
Each creature that starts its turn in the w ebs or that enters them during it s turn must make a Dexterity saving throw (DC14) . On a failed save, the creature is restrained as long as it remains in the w ebs or until it breaks free.A creature restrained by the w ebs can use its action to make a Strength check against your spell save DC. If it succeeds, it is no longer restrained.
The webs are flammable. Any 5-foot cube of w ebs exposed to fire burns away in 1 round, dealing 2d4 fire damage to any creature that starts its turn in the fire.