The Friendly Ball is a use item that allows you to throw a ball. If the ball hits an enemy, they will be captured and taken away from the fight. Once you can use the ball again, throw it and the creature you captured will have a charmed effect. This, unfortunately, is not permanent. The pseudo familiar will follow you around to a degree and attack enemies, if it can. After a few minutes, it will simply leave.
-The Friendly Ball is a direct reference to the Pokémon franchise, inspired off of a device named a 'Pokéball', used to capture wild creatures and make them to fight for you.