This expansion includes the Pet Patrol ruleset and accompanying cards, for Super Dungeon.
Pets are creatures of Crystalia that have joined a Hero in order to help fight the forces of the Dark Consul. Each pet has a specific Hero as their Master, and they are bonded through loyalty and duty.
Perhaps the Pet was once held captive by the Consul and is repaying a debt to the Hero that rescued it. Or maybe the Pet was once a lonely farm animal that has been inspired to greatness by their Hero. Or perhaps a Hero simply has a knack for making friends with adorable forest creatures. Whatever the reason, Pets heed the call of their Master.