The thief was a criminal.
Physical appearance[]
The thief is a skinny adult man with black hair, which got wet after falling in the river, and a short mustache. He is only seen wearing his disguise.
Personality[]
He's a greedy scammer who was in desperate need of money, and was somehow lucky on stealing peoples wallets and valuables do to them getting dropped everytime.
History[]
Scooby-Doo (DC Comics)[]
He needed money, so he went with a scam to go through and steal as much as possible.
The method involved getting a Gondolier to bring a married couple out down the river, and he'll jump out dressed as the Phantom of the Canals to frighten them so badly that they'll drop their wallets and valuables before running away in terror.
He targeted Fred and Daphne when they were on a ride and capsized the gondola to steal Fred's wallet.
He later went after Shaggy and Scooby in an attempt to scare them off, but during their panic he was blinded by a bowl of gelato that got launched out of Shaggy's hand making him get off his gondola and start sprinting down the street to try and pull the bowl off.
Velma took notice of him running and tripped him up causing him to fall into the river.
The thief unmasked.
He was pulled out of the water and was unmasked while he explained his whole scam, and was later arrested.