"Mad Dog" Hashimoto is a martial artist from Japan, with the mentality of a dog.
Mad Dog Hashimoto is an adult, muscular Asian male, with a bald head. He wears a spiked collar and a red and white Gi, which are torn at the sleeves, revealing his muscles.
His personality is the equivalent to that of a bull dog. He barks when he he first sees the gang, but Scooby-Doo discovered that it was easy to make him friendly by throwing him a bone, which he immediately buried.
Scooby-Doo! and the Samurai Sword
He came to compete in the tournament given by Miss Mirimoto, but he was defeated easily by the robot ninjas that attacked at the pre-tournament banquet. He last attended the renovated museum, along with Kerry Kilpatrick and Sapphire Sonja, to see a statue in honor of Scooby-Doo outside.
- DTV13. Scooby-Doo! and the Samurai Sword (no lines)
- Frank Welker is not credited for voicing Mad Dog.