In "Demolition Doofus," it is revealed that SpongeBob has a briefcase for his unicycle. When he jumps into a boat with Mrs. Puff, he folds the unicycle into the briefcase and puts it in the back seat.
Role in series
SpongeBob drives himself to Mrs. Puff's Boating School, then he throws the unicycle into the dumpster because he was certain that he would pass his driving test that day. Later, he is saddened because he threw out his bike and cannot go to the hospital to cheer up Mrs. Puff. However, Gary gets the bike back and he and SpongeBob visit Mrs. Puff.
After SpongeBob fails his last boating exam of the year, he rides his unicycle around in front of Mrs. Puff's school. Later, when Mrs. Puff knocks SpongeBob out of his new boat, he uses his unicycle to keep up with her.
SpongeBob encounters Squidward walking in the middle of the road while riding his unicycle. After finding out that he is going to the hospital to get a nose job, SpongeBob offers him a ride, but Squidward turns this it down. SpongeBob then attaches a trash can to his unicycle to accommodate Squidward.
SpongeBob is seen riding the unicycle as he is making a Krabby Patty delivery at the tank company. Once he reaches that building, he parks the unicycle at the parking rack and goes through the spinning doors.