While the other Animorphs battled around Marco's insides, Marco takes it upon himself to track down a kid who may have taken pictures of the Animorphs morphing. There was just one problem -- Buster, a nasty little pit bull ends up biting Marco. A nasty little pit bull who, we should mention, also has rabies... From Buster, Marco gets rabies. Marco's near death experience actually saved him from the virus. He only appeared in number 42 The Journey. We don't know what happened to Buster at the end of the war. It is very probable that he latter died of his rabies.