Scarlet Ibis

Death Curse. When the scarlet ibis dies, all curses currently inflicted by the ibis become permanent and can be removed only by the remove curse spell or other magic. In addition, the creature that dealt the killing blow must succeed on a DC 14 Charisma saving throw or become cursed with every option listed in the ibis's beak attack. A creature casting remove curse on a creature cursed in this way must succeed on a DC 14 Charisma saving throw or suffer the curses it just removed.

Multiattack. The scarlet ibis makes three attacks: one with its beak and two with its talons.

Beak. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 11 (2d8 + 2) piercing damage. The target must succeed on a DC 14 Charisma saving throw or become cursed. While cursed, the target has disadvantage on ability checks, attack rolls, or saving throws (the scarlet ibis' choice). Alternatively, the ibis can choose for the target's enemies to have advantage on attack rolls against the target. A creature can have no more than one of each kind of curse on it at a time. The curses last for 24 hours or until removed by the remove curse spell or similar magic.

Talons. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 9 (2d6 + 2) slashing damage.