Emanation of Yoth

You call forth a ghost that takes the form of a spectral, serpentlike assassin. It appears in an unoccupied space that you can see within range. The ghost disappears when it’s reduced to 0 hit points or when the spell ends.
The ghost is friendly to you and your companions for the duration of the spell. Roll initiative for the ghost, which takes its own turns. It obeys verbal commands that you issue to it (no action required by you). If you don’t issue a command to it, the ghost defends itself from hostile creatures but doesn’t move or take other actions.
You are immune to the ghost’s Horrifying Visage action but can willingly become the target of the ghost’s Possession ability. You can end this effect on yourself as a bonus action.

At Higher Levels. When you cast this spell using a spell slot of 6th or 7th level, you call forth two ghosts. If you cast it using a spell slot of 8th or 9th level, you call forth three ghosts.