Arnold Stang was, as we all know, the voice of Top Cat. But he wasn't the first voice. Apparently, when the show was developed, the Hanna-Barbera crew had in mind to employ the Phil Silvers-like delivery that their star actor, Daws Butler, also supplied for Hokey Wolf. Daws does not seem to have actually recorded any episodes before the decision was made to seek another voice. Why? When I asked him, Joe Barbera said he didn't recall so we're left to speculate.
Perhaps the studio feared that the show would come out so close to Bilko that someone would sue. It was similar in so many ways and they weren't helping differentiate it by hiring Maurice "Doberman" Gosfeld to supply the voice of Benny the Ball. (Interestingly, shortly after Top Cat ended production, Allan Melvin — who'd played one of Sgt. Bilko's two corporals, became the star of several H-B cartoons…and Harvey Lembeck, who played the other corporal, turned up in a few unbilled roles on Hanna-Barbera shows.) Or perhaps there was the fear that the Hokey Wolf voice was too identified with that character or with kids' shows.
In any case, the studio cast a character actor named Michael O'Shea to play Top Cat. O'Shea was a minor star in 50's television. He was nominated in 1955 for an Emmy as "Most Outstanding New Personality" but lost to George Gobel. (So did another nominee in the category that year, Walt Disney.) Mr. O'Shea was married to actress Virginia Mayo and did mainly bit parts in movies and TV shows throughout the sixties and seventies when, it is said, he also worked for the C.I.A. in an undercover capacity. He does not appear to have done any other animation voicework.
O'Shea recorded four or five episodes of Top Cat before the decision was made to replace him. My pal Earl Kress and I have wondered if at any point, they considered giving the role to Jerry Mann, an actor who was doing some work for the studio at the time, usually supplying a voice that was in the Phil Silvers ballpark, though not as close as Daws' semi-impression. Barbera seems to have liked Mann's Silvers-like voice and employed it in several installments of The Flintstones, including giving it to Dino in the one episode where the loyal pet spoke.
Arnold Stang was an odd choice, as he was usually associated with milquetoast, whiny characters and Top Cat was a cool, confident fellow. But someone thought he was worth a read and when he auditioned, Hanna and Barbera liked what they heard. Before the week was out, they had him signed and he re-recorded the relevant lines in the shows that had already been done. He was quite wonderful in the part. (Ironically, a few years after the show was cancelled, Arnold relocated to the East Coast and so he was unavailable when H-B featured Top Cat in a guest appearance on a kids' record. When that happened, they usually had Daws Butler do the Hokey Wolf voice…and Daws also used it in one episode of Top Cat where he played a rival con-man/feline. Arnold did return to do T.C. in the 1985 series, Yogi's Treasure Hunt.)
While we're talking Stang Voice History: Many obits note that Arnold was the voice of a character called Shorty who served for a time as Popeye's sidekick in wartime cartoons produced by Famous Studios. They make it sound like a long, important gig. Just for the record, Shorty only appeared in three cartoons and Arnold only did his voice in the third, Moving Aweigh. The first two were Happy Birthdaze and Marry-Go-Round, and Jack Mercer supplied Shorty's voice in them. The character looked a little like Arnold (more so in the third cartoon) and sounded a little like Arnold even when Mercer did the role…but though Arnold was heard in many Famous Studios cartoons, including a few other Popeyes, he only played Shorty in one.