Argus Filch is a character that does not appear in Potter Puppet Pals. He is mentioned in the episode Wizard Angst. He has a cat and smells like pizza. Harry writes about him :

Filch has a cat and smells like pizza and poop and always poops his pants all the time and smells like broccoli and poop. His cat , Ms.Norris smells like poop and fish soup.