Werehyena

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

Shapechanger. The werehyena can use its action to polymorph into a hyena-gnoll hybrid or into a hyena, or back into its true gnoll form. Its statistics, other than 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.

Multiattack (Gnoll or Hybrid Form Only). The werehyena makes two attacks: one with its bite and one with its claws or scimitar.

Bite (Hyena or Hybrid Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) piercing damage. If the target is humanoid, it must succeed on a DC 12 Constitution saving throw or be cursed with werehyena lycanthropy.

Claws (Hybrid Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8 (2d4 + 3) slashing damage.

Scimitar (Gnoll or Hybrid Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) slashing damage.