BetoBeto-Kun

Audiophile. Whenever the betobeto-kun hears a creature that it hasn’t encountered before, it must make a DC 11 Wisdom saving throw. On a failed save, the betobeto-kun
loudly mimics the creature's noises for the next 10 minutes, automatically failing Stealth checks against creatures that can hear it.

Jumpscare. If the betobeto-kun is hidden from a creature when it uses
its Frighten action on it, the creature has disadvantage on
the saving throw.
In addition, when one or more more creatures become
frightened by the betobeto-kun, the betobeto-kun gains
2d6 temporary hit points, which last for 1 minute. When
the betobeto-kun’s tamer reaches 5th level, these temporary
hit points increase to 3d6.

Shadow Armor I. While in dim light or darkness and not wearing any armor,
the betobeto-kun gains a +2 bonus to AC.

Shadow Stealth. While in dim light or darkness, the betobeto-kun can take
the Hide action as a bonus action.

Frighten. The betobeto-kun attempts to scare a creature
within 5 feet of it by making a sudden movement and a loud
noise. The creature must succeed on a DC 12 Wisdom
saving throw or take (2d8) psychic damage. A creature
automatically fails the saving throw and is frightened of the
betobeto-kun until the end of the betobeto-kun's next turn if
it rolls a 1 or lower on the d20.