The Conch Signal resembles a regular conch shell except much bigger in size. It is also light purple in color.
According to SpongeBob, it notably appears in "The Adventures of Mermaid Man and Barnacle Boy" series.
SpongeBob then wins it in a contest.
After SpongeBob abuses its power, Barnacle Boy takes it and plans to burn it with his heat vision. It is unknown if he does so.
Role in the episode
After winning a contest, SpongeBob wins the Conch Signal. He uses it to see if it works. This causes Mermaid Man and Barnacle Boy to hear it and come to SpongeBob's house. They warn SpongeBob that it is not a toy and should only be used in emergencies. SpongeBob uses it to call them so that they can open a jar of pickles. Barnacle Boy is angry that SpongeBob has used it in a false alarm. Mermaid Man convinces Barnacle Boy to let SpongeBob use the conch for minor things because superhero emergencies do not come up very often. SpongeBob uses the Conch Signal several more times until the super duo is tired. Barnacle Boy takes the Conch Signal and tries to burn it with his heat vision, but is unable to because of his age. He then puts it in his pants and says that he will destroy it later.
This Conch Signal might be the alternative to the Mermaid Man Signal shown in "Night Light."