Coral Carnival is a carnival that appeared in the episode: Stuck in the Wringer. SpongeBob and Patrick went there. Some people like Nat Peterson, Harold, Billy, Billy, Shubie, Evelyn and many more went there. SpongeBob yelled at Patrick because his Wringer and SpongeBob got stuck to Patrick's Forever Glue. It is unknown if the Carnival will re-appear in future episodes.
The Coral Carnival is open all year round, but Patrick thought it was only open a certain time of the year.