The Cup of Invincibility - S1.E20

Louxos and Kerberos, two fearsome werewolves, turn up on Earth in search of a silver cup that will make them immune to silver! And Henri de Lachasse just happens to have organized a dog contest the first prize of which is the famous cup! Tara, Cal and Sparrow must find a way to enter the contest, and what could be better than entering Manitou!