The episode has shown characters that had certain types of phobia:
1) The fear of clowns, which plays a big part in this episode, is called "coulrophobia."
2) We learn that Grandpa Max used to be afraid of heights a long time ago, but got over it by climbing a water tower. The fear of heights is usually described as "acrophobia," "aerophobia," or "altophobia."
3) Zombozo is shown to be afraid of ghosts, and is easily defeated by Ghostfreak in this episode. Phasmophobia or spectrophobia usually describes the fear of ghosts.