The Ghost of Soda Drink Hats is a ghost who appears in the episode "One Krabs Trash."
It is actually Mr. Krabs with a fishing rod holding a poorly drawn picture of a ghost with a shopping list on the other side.
The ghost was another scheme Mr. Krabs used to try and get SpongeBob to give him his hat back. He told SpongeBob that the hat he possessed was cursed. He told him he had to return it to its original owner, Smitty Werben Jagerman Jensen.