John is revealed to be the spirit of the Titans bathroom in the "Serious Business" episode. Although this is the first time he has revealed himself, technically, John has been featured in many episodes, such as "Breakfast Cheese".
He doesn't seem to be either a friend or villain to the Teen Titans... however, Beast Boy did show some familiarity with him, as when John appeared, Beast Boy said "What's up John?", while the other Titans were shocked to see their bathroom talking to them.
After the Titans abused their bathroom privileges, John appeared on the tiled wall of the shower. Apparently, he was a magical being, claiming that he, along with his other bathroom brethren, came from another world that had been destroyed long ago. His species made a new home on Earth. John was upset on how the people of Earth took the bathroom for granted, and that he appreciated the planet but gets no acknowledgement in return. John then went on scolding Robin and the other Titans on how they had turned a place of magical fun into one of strife.
Afterwards, he announced that he and his kind will leave the world forever due to the lack of Earth peoples' thanksgiving for them, and proceeded to detach the his whole self (the entire bathroom, walls and everything), breaking away from the Titans Tower (leaving a gaping hole in the center of the Tower). All the other bathrooms in Jump City, and presumably the world, disconnected from their homes and followed John to the outermost edges of the atmosphere. The heroes watched with awe, as hundreds of bathrooms ascended into the sky. Robin said with emotion that they are finally going home, but Starfire pointed out that the bathrooms' world was destroyed... so Robin really had no idea.
In space, John and all the other bathrooms joined hands, forming a huge circle over the planet. Suddenly, they started to revolve counterclockwise at a sound barrier-speed. In unison, they rocket off into the distance, where they expectantly find another planet to live on. With nothing left to do, and in need of the bathroom, Raven hatches an idea; they all break out into the Pee Pee Dance.
- Serious Business (speaking debut)
- Shrimps and Prime Rib (cameo)
- His name is pun on the term "The John", which is used to refer to the toilet.