Scooby-Doo and a Mummy, Too Scooby Doo, Where Are You! : Season 1 Episode 12

The gang, at the college museum, gets the lead on a dead Egyptian ruler named Inca. According to an ancient superstition, if he were ever removed from his crypt, he would turn the people who moved him into stone. Shaggy finds a rare coin that the Professor is trying to study. The trouble begins when Shaggy accidentally takes the coin and the mummy is on the loose looking for it.