One day, Seth and his brother went into the wooded area located on their family's property. They found a hole with a weird gravitational pull to it. They eventually were both sucked inside after the gravitational pull strengthened. This hole pulled them into a wormhole and transported them to Bikini Bottom.
Seth seems to be down in the dumps often. He also seems to be hardworker and smart, but still friends with SpongeBob, Patrick, and Caleb. He puts up with Caleb's nonsense because he is his brother, but is often annoyed by him. He seems to also get overly excited at times. He also is scared very easily and naive at times.