1. They replaced Pat Priest because she was too old.

Pat Priest, the second and best-known actress to portray Marilyn Munster, was about to turn 30 years old at the time of filming the movie. The age-obsessed Hollywood producers wanted a younger performer in the role. Enter Debbie Watson, a teenager who had previously starred as the title characters on the sitcoms Karen and Tammy. It was Watson's only appearance as Marilyn.

2. Debbie Watson graduated high school during production.

Munster, Go Home! had a hurried production schedule of just a couple of weeks in the spring of 1966. In that tight window, Watson celebrated a milestone — she graduated high school. The cast and crew took time to throw a little party for the actress, including a specially made ice-cream cake from Baskin-Robbins. It was shaped like a coffin and featured three little Munster figurines (Grandpa, Herman, Lily) lying inside it.

3. The Drag-U-La was made with an illegally purchased coffin.

Reportedly, according to legend, a real coffin was used to make the awesome DRAG-U-LA hot rod seen in Munster, Go Home! The only catch that it was supposedly illegal to purchase a coffin without a death certificate in the state of California at the time. Richard “Korky” Korkes, the man who built the dragster, claimed he passed money under the table to a funeral home in North Hollywood, who left a coffin for him outside the back door.

4. Eddie got a bright new outfit.

With the bold leap to Technicolor, the production looked to make the characters pop off the screen. The television show was in black-and-white, so viewers had no knowledge of the "real" color of the Munsters wardrobe. However, Eddie (Butch Patrick) wore a dusty, greyish velvet jacket on the TV series. In the movie, he sports a bold purple look.

Image: The Everett Collection

5. Lily had a makeover, too.

Speaking of hair turning white — or the opposite, in fact — let's discuss the look of Lily Munster (Yvonne De Carlo). In the early episodes, Lily had a different look. Her original necklace, a sort of star shape, was replaced with her iconic bat pendant. Her eyebrows were given a more upward curl. Munster, Go Home! also gave us a good look at her green skin tone, which was eventually made pale white in subsequent reboots.

Image: The Everett Collection

6. It was the big-screen debut of Jack Dodson.

Dodson was a fairly fresh face to audiences. The actor had just recently made his first appearance as Howard Sprague on The Andy Griffith Show, in the March 1966 episode "The County Clerk." Munster, Go Home! gave the goofball performer his first-ever film role. Too bad he was not credited for the work! His name does not appear in the closing credits.

7. Dodson was not the only familiar Mayberry face.

Eagle-eyed fans of The Andy Griffith Show can spot other familiar faces that popped up in Mayberry. Bernard Fox (Malcolm Merriweather) is the most obvious, but there are deeper cameos. George DeNormand, uncredited as "Man at Customs," played George Bronson in the Andy episode "The Clubmen." Robert Ball, who portrayed a ship steward alongside Jack Dodson, was also Oldfield in "A Visit to Barney Fife." Cliff Norton, who has a small credited role as Herbert, turned up as Wally in "Goober's Replacement."

8. This hearse pointed out a casting inconsistency.

At the start of the movie, you will spot the names "Gateman, Goodbury & Graves" on the back door of the hearse that delivers Herman to Mockingbird Lane. This is an easter egg for Munsters fans, who will know Gateman, Goodbury and Graves Funeral Home as the place where Herman works on the sitcom. Legendary character actor John Carradine portrayed Mr. Gateman on the series. However, in Munster, Go Home! Carradine plays the role of Cruikshank.

9. This iconic ship was soon decommissioned.

The Munsters set sail for England aboard the SS United States, a historic commercial liner that set the speed record for crossing the Atlantic Ocean. The ship was the largest ocean liner constructed entirely in the United States. Munsters, Go Home! recycled stock footage of the boat. The ocean liner was put out of service in 1969, three years after the film was released.

10. Robert Pine's mother-in-law was a Universal Monster movie icon.

You might recognize Pine as the sergeant on CHiPs and father to Chris Pine, the modern Captain Kirk. Munster, Go Home! offered young Pine one of his earliest screen roles. His family had ties to Universal horror. His mother-in-law is Anne Gwynne, a "scream queen" who appeared in classics like Black Friday (1940) and House of Frankenstein (1944). And if you are wondering — no, Anne Gwynne is not related to Fred Gwynne.