Bouda

Shapechanger. The bouda can use its action to polymorph into a hyena-humanoid hybrid or into a hyena, or back into its true form, which is humanoid. Its statistics, other than its AC, are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Keen Hearing and Smell. The bouda has advantage on Wisdom (Perception) checks that rely on hearing or smell.

Glowing Eyes and Teeth. Bouda are child-eaters, despoilers of purity and family. Resembling oversized gnolls, a web of scars along their muzzles is evidence of their gluttonous eating habits. Forever leering, their teeth glow as yellow as their eyes.

Fly-Bedecked Shapechangers. Bouda lurk on society’s fringes, shapechanging to blend in with mortals. They seek out happy families, consuming the children in the night and leaving gruesome trophies behind. They may mark a victim nights before attacking to terrify the helpless parents.

Gluttons. Bouda have a weakness: they are incorrigible gluttons. When presented with a fresh corpse, even in combat, they will attempt to gorge on it or at least defile it for later consumption. Bouda are vindictive, seeking revenge on anything that drives them from a kill.

Multiattack. The bouda makes one bite attack and one mephitic claw attack.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8+4) piercing damage plus 10 (3d6) poison damage.

Mephitic Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target.  Hit: 11 (2d6+4) slashing damage, and the target must make a successful DC 15 Constitution saving throw or become poisoned for 1 round by the visible cloud of vermin swarming around the bouda’s forearms.

Ravenous Gorge. The bouda consumes the organs of a corpse in a space it occupies. It gains temporary hit points equal to the dead creature’s HD that last 1 hour. Organs consumed by this ability are gone, and the creature can’t be restored to life through spells and magical effects that require a mostly intact corpse.

Innate Spellcasting. The bouda's spellcasting ability is Charisma (spell save DC 13, +5 to hit with spell attacks). It can cast the following spells, requiring no material components:

Constant: detect evil and good, detect magic
At will: thaumaturgy
3/day each: darkness, expeditious retreat
1/day each: contagion