Octo Ring (5e Equipment)
From D&D Wiki
When you put on this ring, you are instantly transformed into a normal-looking octorok. You remain in this form until you use your action to end the effect, causing you to return to your normal form with the octo ring in your palm.
While transformed, most of statistics are replaced with those of the chosen octorok, but you retain your same total hit points. Your mental ability scores—Intelligence, Wisdom, and Charisma—are not reduced if they would be higher. You retain your alignment and personality.
While in the form of an octorok, your gear melds into your form. You can't activate, use, wield, or otherwise benefit from any of this equipment, other than the octo ring.
You are limited in the actions you can perform by the nature of your octorok form. You can't speak, cast spells, or take any other action that requires hands or speech.