The Ghost of Soda Drink Hats is a paper ghost who only 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. Mr. Krabs shook and waved the paper to make it look like the ghost was moving. Despite its fakeness, SpongeBob never noticed it was a trick by Mr. Krabs.
The ghost was another scheme Mr. Krabs used to try and get SpongeBob to give him his hat back. Mr. Krabs attached the paper ghost onto a fishing rod and hung it inside SpongeBob's bedroom window for him to see it. SpongeBob thought he was a floating shopping list at first because the paper was turned the opposite way. After turning the paper, 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 who was "number one in Bogeyland" or the hat will curse him. When SpongeBob asked if he should really give it immediately, the ghost shook up and down yelling. Mr. Krabs didn't realise that Smitty was real and meant for SpongeBob to give it to him.