The Viking ghosts were the disguises of Mr. Hansen and two unnamed geologists in "The Curse of the Viking Lake", the second-season premiere episode of The Scooby-Doo Show.
The gang traps the Vikings, revealing them to be Mr. Hansen and the two supposedly missing geologists. The geologists had discovered uranium on the lake shore, and devised a scheme (along with the museum curator) to scare off any guests. They used the natural steam from the caves to run their machinery.
- The costume of the chief Viking ghost was on display at the Coolsonian Criminology Museum.
- In the Norwegian dub, the chief Viking ghost was voiced by Helge Winther-Larsen.