Duskfog

The duskfog can occupy another creature's space and vice versa. In addition, if air can pass through a space, the duskfog can pass through it without squeezing. Each foot of movement in water costs it 2 extra feet, rather than 1 extra foot. The duskfog can't manipulate objects in any way that requires fingers or manual dexterity.

Melee Spell Attack: +3 to hit, reach 5 ft., one creature. Hit: 13 (3d6 + 3) necrotic damage and the duskfog regains hit points equal to half of the necrotic damage dealt.