Epics are pets in the game that can only be obtained by buying a toy and scanning the code that comes with whichever pet you chose to purchase. They have extraordinarily good stats, and by buying them, you can use a certain EPICS Supermove depending on which epic you have. They are of matching elements to their wielder.
The Toy Merchant sells epic themed merchandise. He appears in multiple places, and you might easily find him.
"Fighting together with the other four EPICS, this [epic name] helped save the Prodigy World from the Puppet Master and its goons. However, using its element, it could control [element], it banded with others. Defeated by the Puppet Master's Army, they failed to save Prodigy Island. They were sent into their statue forms, and only revivable if you buy them and activate them using their code."