A Belle Tolls is a quest that can be found in Epic Mickey: Power of Illusion.
Beast will ask for Mickey's help in tracking down Belle.
Belle can be found in Agrabah, in an area where a Golden E-Ticket can normally be found in the first half of the level. Mickey can leap on a Palace Guard's head to reach her.
When she returns to Beast's Room, Mickey will be given a Paint Upgrade and a Room Star the next time he speaks to Beast.