This is a standalone episode as it aired as part of the Patchy the Pirate hosted special, "SpongeBob B.C." (Before Comedy). Although it is part of the seasons 1-3 pre-movie golden era of SpongeBob episodes, it is often listed by fans as one of the show's worst episodes.
To be honest I don't think it is one of the worst, but it's not the best either. It's a decent episode.