I'm a Believer is the 42th episode of the finale season alongside with the episode Liar, Liar, You For Hire?.
For the first part of the episode, K'nuckles blames things he does on ghosts. Peppermint Larry believes in ghosts, and holds a séance-like event along with Flapjack to prove his theory. He also gives Flapjack the card for Stormalong's resident ghost specialist, Jaude. That night, K'nuckles says he knows ghosts don't exist because on his eighth birthday, his grandpaps said he would come to K'nuckles' birthday, living or dead. For some reason, no one came to K'nuckles party. Flapjack goes to Jaude to speak to ghosts, and prove that they're real to K'nuckles. Later that night, Flapjack takes some candy from Bubbie's mouth and goes off somewhere. This time, K'nuckles goes to Jaude to reclaim his candy, but Jaude doesn't have it. When he returns to Bubbie, he sees Flapjack crying in Bubbie's arms. Flapjack seems to have saw a ghost, the ghost of grandpaps! They go to grandpaps, only to find out that he is still alive, and K'nuckles' party (which was only a week ago), was held at grandpaps' house. It also turns out that the candy Flapjack took was for another birthday party for K'nuckles, which is today! But the candy is missing! Jaude is found sitting on the floor eating. He says "Must've been a ghost!", and he fades away, proving he is a ghost.
- Debut of K'nuckles's grandfather Grandpaps.
- Jaude is a ghost.
- The first time Peppermint Larry reference Anton St. Germain and Wiggler without changing his voice. Although this is his first time referencing Angry Wiggler.
- The episode Bam! aired directly after it on July 19, 2010, rather than the second half of the episode, Liar, Liar, You For Hire?.
- The episode is named after the song produced by The Monkees.