Boowray

Incorporeal Movement. The boowray 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.

Invisibility. The boowray is invisible.

Keen Smell. The boowray has advantage on Wisdom (Perception) checks that rely on smell.

Evil Whisper. Whenever a creature influenced by the boowray takes an evil action or acts upon negative emotions, the creature must make a DC 13 Wisdom saving throw. On a failed save, the creature's alignment shifts one step toward lawful evil. If the creature is already lawful evil, it takes 7 (2d6) psychic damage from the boowray's manipulative influence. On a successful save, the creature resists the influence for now.

Inscrutable Alignment. Spells and magical effects that detect alignment don't reveal that the boowray's alignment is lawful evil, but it appears to be of the alignment of its victim.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 2 (1d4) piercing damage.

Whispering Manipulation. The boowray can cast the suggestion spell (spell save DC 13) on a creature it can see. The target automatically fails its saving throw if the boowray's Keen Smell is activated. Once it uses this ability, it can't use it again until it completes a short or long rest.