The Flying Dutchman is a recurring character that appears on and off throughout the show. The Flying Dutchman is usually an antagonist for most episodes. He first appears in "Squidward the Unfriendly Ghost" in a magazine, but his first, real, physical appearance is "Scaredy Pants."
The Flying Dutchman is a ghost with a green aurora all around him. He has a beard, and yellow eyes. The Flying Dutchman also has a pirate hat with a piece if it missing, and a coat. He also has a bag starpped on that is marked "souls". He doesn't have any legs, and his body ends in a "tail".
The Flying Dutchman is shown to be rather evil in most of the episodes he appears in. An example is in "Scaredy Pants" where he attempts to take the souls of everyone in the Krusty Krab because of SpongeBob ruining his image. While the Flying Dutchman takes strong delight in scaring people, he doesn't live exclusively to haunt mortals, having sometimes tormented them only out of boredom (scaring SpongeBob for months to wait for his ship to be fully repaired), or otherwise because someone had provoked him.