It is similar in shape to a Port-A-Potty. It is painted yellow, has a wooden door with a string handle, a netted window on the door and right center of the bathroom, and a clam sign with red lettering similar to that of the Krusty Krab's.
SpongeBob takes Bubble Buddy to Goo Lagoon, and then places him inside the portable bathroom since he supposedly has to go, much to the frustration of the people waiting in line to use it. He leaves him in there for 2 hours.
It makes appearances in several other episodes taking place at Goo Lagoon.
The player can use it to switch from one character to another, the purpose being that the player may need to switch into another character in order to defeat an enemy with a certain attack or go past obstacles that can only be crossed by using a certain character's powers.