Blight

Amorphous. The shadow can move through a space as narrow as 1 inch wide without squeezing.

Shadow Stealth. While in dim light or darkness, the shadow can take the Hide action as a bonus action.

Grappling Bite. Whenever the Blight hits with a melee weapon attack, the targeted creature must make a D.C. 12 Acrobatics of Athletics check or be grappled, the Blight has +1*the number of turns grappled by blight on attack rolls.

Strength Drain. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 9 (1d6 + 2) necrotic damage, and the target's Strength score is reduced by 1d4. The target dies if this reduces its Strength to 0. Otherwise, the reduction lasts until the target finishes a short or long rest.