<Tr> <Td> SDD - 16 </Td> <Td> "The Spirits of' 76" </Td> <Td> The Ghosts of Benedict Arnold, William Demont and Major John Andre </Td> <Td> December 18, 1976 </Td> <Td> While in Washington D.C., the kids visit the Smithsonian Institution, but lose Scooby and get locked in after hours . While searching for Scooby, they find strange goings on at the museum, like a locomotive moving on its own, and the ghosts of Benedict Arnold, William Demont and John Andre haunting the building . </Td> <Td> Mr. Clive, Mr. Willit and a henchman </Td> </Tr> <Tr> <Td_colspan="7"> Notes: <Ol> <Li> These episodes guest - star Scooby - Dum . </Li> </Ol> <Ol> <Li> Episode SDD - 12, "There's a Demon Shark in the Foggy Dark", was originally broadcast not on a Saturday morning, but on Thanksgiving Day 1976 (November 25), during ABC's Thanksgiving Funshine Festival . </Li> </Ol> <Ol> <Li> These episodes, and all first - season repeats, were broadcast as part of The Scooby - Doo / Dynomutt Show, which included an additional half - hour featuring a Scooby - Doo, Where Are You! rerun . </Li> </Ol> </Td> </Tr> <Ol> <Li> These episodes guest - star Scooby - Dum . </Li> </Ol> <Li> These episodes guest - star Scooby - Dum . </Li>

Who was that cat creature i saw you with last night