Mr. Grouper has appeared in every episode but his main character appearances are:
- Happy Holidays, Mr. Grumpfish!: He narrated the story and his character in the story, Mayor Grouper, helped the Bubble Guppies to get Mr. Grumpfish to show some holiday spirit.
- The Puppy And The Ring: He played the Sun King, whose Sun Ring gets stolen by The Night Wizard and his Lobster Soldiers. While he did not get as much screen time as the other characters, his character and stole item played an important role in the plot. He also lead the ending song for the special, A Brand New Day!.