Dagger of Yysmoira (5e Equipment)
From D&D Wiki
Weapon (dagger), rare (requires attunement)
An ornate dagger of mithral is fey in origin and was bequeathed to the aspiring diplomat and spy Yysmoira Veyln as a symbol of her pact until her botched attempt to supplant her patron.
You gain a +1 bonus to attack and damage rolls made with this magic wepaon.
Gleaming: This item never gets dirty.
Ambitious. When you are presented with an opportunity to acquire material wealth or status, this item heightens your urge to do so. As a bonus action you may roll 1d6 and add the result to a Charisma (Persuasion) check, Charisma (Deception) check, or Charisma saving throw, once you use this ability, you cannot do so again until the next dawn.
Ring Form. As a bonus action you can speak a command word to transmute the dagger into the form of a ring which appears on your finger. You may speak the command word while it is in its ring form to turn it back to a dagger. If the ring was on your finger, it appears in your hand.