Shadow Demon

The demon can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.

While in bright light, the demon has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

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

Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 10 (2d6 + 3) psychic damage or, if the demon had advantage on the attack roll, 17 (4d6 + 3) psychic damage.