In The Addams Family episode "Cousin Itt and the Vocational Counselor," something unusual happens, but unless you’re a huge fan of the show, you most certainly missed it.

Actor Richard Deacon appears in the episode as a career counselor to Cousin Itt named Mortimer Phelps, and his appearance on The Addams Family is decidedly out of place for a very particular reason.

This was an unusual casting choice on The Addams Family because the previous year, Deacon had appeared on The Munsters as a city official, and the shows — locked in rating wars and constantly compared — had fallen into a practice of practically never hiring the same guest stars.

The Addams needed every casting decision they made to help them appear distinct from The Munsters.

That’s why you won’t see actors like Ellen Corby or Parley Baer or Margaret Hamilton cross the line in the sand and appear on The Munsters. They are firmly on team Addams.

This rivalry started in 1964, when both The Addams Family and The Munsters premiered, the newest fantasy-comedies on the block. And as the offbeat sitcoms would run for almost exactly the same amount of time, often there were comparisons drawn between the two shows.

Most put off by these comparisons was The Addams Family star John Astin, who told The Capital Times in 1965 how much he hated seeing the two shows lumped in the same category.

The way that Astin saw it, The Addams Family had the upper hand as must-watch TV, and if you look back through reviews, most critics do seem to agree with the Gomez actor and side with The Addams Family as the superior show.

"You see, The Munsters are monsters on the outside, but perfectly normal people in every other respect," Astin said. "The Addams Family, on the other hand, are not monsters at all, but terribly daffy in almost every respect. Like the Addams cartoons, our show is an attack on the cliches of life, a reverse joke."

Astin’s loud protests against comparisons to The Munsters didn’t stop most casual viewers from considering the shows the same.

In 1966, The Family Circus cartoonist Bil Keane even drew a comic of a middle-aged couple squinting at a TV set with the caption: "It looks like we’ve tuned in to either The Munsters, The Addams Family or Phyllis Diller."

Clearly, Keane’s joke was meant to poke fun at Diller’s wild style, but his punchline depends on audiences being very familiar with thinking of The Munsters and The Addams Family as interchangeable.

Astin can attest that he wasn’t the only one on the cast who didn’t enjoy these ceaseless, and in The Addams Family’s opinion, baseless comparisons.

"None of us enjoy being compared with the Munsters," Astin said.

But Deacon isn’t the only one who made the rare crossover to appear on both fantasy shows. Actor Vito Scotti appeared four times on The Addams Family and also provided voice acting on The Munsters, and Don Rickles did an episode of each.

How many guest stars can you think of who appeared on both shows?