Mike Geller is the owner of Mike's Diner.
He is a short man with bushy hair and a beard.
His personality is kind, however he is revealed to have been very greedy at the end.
Scooby-Doo! Original Mysteries
He told the Scooby gang about the Creepy Conductor, and also feeds them some food at his diner. He is later is revealed to be the Creepy Conductor. He kidnapped the tour guide. (Mystery Inc. Rides Again)