I ADVISE YOU NOT TO MIX SPECIES! Mixing species is very bad, especially when one species is larger than the other. I have kept both American Toads and Leopard Frogs, and trust me, Leopard Frogs will eat anything. Keep the American toad in a separate tank, at least a 10 gallon, keep the leopard frog in a separate tank, at least a 10 gallon. For a toad you will need at least 3 inches of dirt for them to burrow in. Also, have a shallow water dish. For the leopard frog, have a half land half water setup. Hope this helped.