The Billabong Bunyip / The Subhuman Substitutes

A) A new gym opened in Mona's city and the manager is Bruce, a guy from Australia. Everyone, but Mona, Charley and Lily, begins to do exercise at the gym. Mona notest that everyone is very tired, then realizes that the Billabong Bunyip, a creature from Australia, is sucking everyones energy. B) Miss. Gotto is sick and the kids get a substitute teacher. Soon all their teachers are sick too and the kids keep on getting new substitute teachers, but are they twins or what? Every substitute teacher is just like the other. Mona, Charley and Lily discover that the teachers are aliens and now they have to stop them.