Band of the Anser

An ivory band with a golden inlay, this ring appears simple yet elegant to the untrained eye. A creature with True Sight can read an inscription on the inner surface of the ring, written in infernal, which simply reads honk.

Smooth as Jazz.
A creature that attunes to the ring gains a 1d4 bonus to Sleight of Hand (DEX) checks when committing acts of thievery.

Honk
Once per day, the wearer can use the ring to generate an ephemeral, distracting "honk" sound within 50 feet of itself, granting advantage on a Stealth or Sleight of Hand ability check. This ability resets at dawn.

The Horrible Goose

A creature that attunes itself to this ring becomes cursed, haunted by the occasional sound of fluttering wings and faraway honking that only they can hear. When a creature activates either of the ring's abilities for the first time, there is a 5% chance that they will be visited by The Goose within the next day.

Appearing from the shadows, The Goose manifests within 300 feet of the ring bearer and attempts to pilfer an item of value from them or their group or harasses them by flapping its wings and honking, which imposes disadvantage on stealth checks for all creatures within 15 feet of The Goose. If the wearer removes the ring, there is a 60% chance they awake the following morning to find it back on their finger, having been replaced by The Goose as they slept.

For every day that passes without the ring bearer attempting to steal something using the ring (after its initial activation), the odds of The Goose appearing increase by 5%. The Goose is a Fiend, whose physical form uses the Raven stat block, but with a +3 DEX score and +6 on Stealth/Sleight of Hand checks. If it is reduced to zero HP, the avatar of The Goose is not killed, but returns to the Abyssal plane, disappearing in a puff of smoke with an echoing 'honk,' and cannot reappear until after the next dawn. The ring itself is immune to all non-magical damage and resistant to all magical damage types. The curse can only be removed by a Remove Curse spell, cast by a creature capable of casting 6th-level spells or higher.

Note: the DM can, at their discretion, increase the period between percentile increases based on the importance/value of a stolen item. Additionally, the form this cursed item takes can also be that of a ribbon, to be worn around the neck (the item then becomes the Periapt of the Anser or The Anser's Ribbon).

Notes: Bonus: Sleight of Hand, Advantage: Ability Checks, creature, difficult to remove once attuned, Cursed, Jewelry