The following characters appeared in the episode "Super Cat Ears":
Catboy is in the museum, guarding a book that Night Ninja intends to use to boost his powers. Thankfully, Catboy tells the viewers that he has amazing hearing thanks to his Super Cat Ears, so he will need to use them to listen for any suspicious sounds. Soon enough, his Cat Ears pick up the sound of a pin dropping at the other end of the library. He runs towards the sound, only to see a Ninjalino responsible for it. However, this was part of Night Ninja’s plan to distract Catboy. Now unguarded, the villain steals the book and makes his getaway.
Going back to the time before Catboy uses his Super Cat Ears, Catboy says that if he ignores random sounds that aren’t important, then he won’t get distracted from his main mission. With that, when Catboy uses his Cat Ears, he hears pins dropping at the end of the library, maracas shaking three floors away, and a trumpet playing in the rooftop, all done by the Ninjalinos. Catboy pays no attention to all those sounds; what he does pay attention to is incoming footsteps from Night Ninja. He hides behind the desk, and before the villain can kick the glass frame, Catboy scares him away.
With Night Ninja and the Ninjalinos gone, Catboy goes up to the rooftop. He plays the trumpet left behind and states that he likes the sound of it, ending the short.
Ignoring other sounds is good to prevent being distracted in an important situation.