According to IMDB, his name is Bob McQuain and he appeared in 14 eps!

From IMDB bio:

Mr. McQuain's big break came when he appeared in an outdoor theatre production in North Carolina, in a role in which actor Andy Griffith had got his own early start. When Mr. Griffith returned to NC for a visit, he caught a performance and met Mr. McQuain. This lead to a subsequent casual friendship as well as several small parts on the 1960s "The Andy Griffith Show."

- The Big House...Lieutenant
- Andy's English Valet...Fletch Roberts
- Barney and the Governor...Postal Clerk
- Lawman Barney...Joe Waters
- Aunt Bee the Warden...Ike Gordon
- The Merchant of Mayberry...Joe Waters
- A Medal for Opie...Joe Waters
- Jailbreak...Newlywed Man
- The Manicurist...Manicure Customer (uncredited)
- The Farmer Takes a Wife...Joe Waters
- The Clubmen...Jim Baker
- Barney Gets His Man... Sgt. Johnson
- Andy Forecloses...Bill
- Ellie Saves a Female...One of the Jenkins men.