Ball of Returning

When finding this small, multicolored ball for the first time one chooses a command word for it. This word magically appears on the ball, when thrown by someone they have one minute to utter the command word. Regardless of where the ball is, so long as it remains within one mile of the thrower, it will do all it can to return to the thrower. If the ball is held in a non-magical container roll 1d20 every 6 six seconds (or one round of combat) as it attempts to escape. If a natural 20 is rolled, whatever container that holds it has a hole the dimensions of the ball and it continues on its way to the thrower. Creatures holding the ball must make a contested athletics (DC 15) to keep their grip on the ball. The ball will continue to try to reach the thrower that has called it unless it is thrown again and called to the new thrower or a minute has passed. This ball has an AC of 10 and 2 HP. If it is destroyed the enchantment becomes useless.