Ricky Asks For a Raise - S1-E35
Character mistake: After Tropicana nightclub owner Mr. Littlefield replaces Ricky Ricardo with Xavier Valdez, "the Konga King," Lucy, Fred and Ethel try to get Ricky's job back by going to the nightclub in a succession of different wigs and costumes, then leaving when they learn that Ricky is no longer performing there. At one point, Fred and Ethel enter the nightclub, posing as "Mr. And Mrs. Crumley." A disguised Lucy enters one minute later and is outraged to hear that Ricky is no longer there. Ethel then pretends to phone a friend to tell her to not come to the nightclub. Lucy says, "Attagirl, Mrs. Crumley." However, when Ethel had told the maitre d' she had a reservation for "Crumley," Lucy had not yet entered and therefore should not have known that name.
Suggested correction: During the point when Mrs. Crumbley wants to call her friend to get her friend to cancel her reservations as well, Mr. Littlefield says, "But Mrs. Crumbley," to protest as she walks to the phone to make her call. So he did say her name in front of Lucy, thus giving her the name to reply with, "Attagirl, Mrs. Crumbley."
Character mistake: Geraldine's name changes from "Boudicca Geraldine Granger" to "Geraldine" but with multiple middle names from Mary Poppins with the surname "Granger."
The Purple Panther: Part 1 - S3-E6
Character mistake: In the song 'The World Goes Round', Stingy sings about dinosaur bones from the Stone Age (the second verse). The dinosaurs were wiped out about 65 million years ago while the Stone Age started 2.5 million years ago, an obvious time gap.
When in Rome - S1-E3
Character mistake: Nobody in this scene knows how to dance the tango that is playing. (00:16:35)
The M.O.D.O.K. That Time Forgot! - S1-E2
Character mistake: M.O.D.O.K. refers to Hoobastank as "the Beatles of the late 90's." Hoobastank only released one album in the 90's, and they didn't become popular until after they released their second album in 2001.
Character mistake: When talking to Will on the phone, Grace misuses the term "pied-à-terre" (which means "apartment" in French) instead of "pas de deux" (a dance for two) while describing the delicate and complex nature of a relationship between two gay men. When Will points out her error, she says she knows what pied-à-terre means because she took Spanish in high school. However, in season 1, episode 20 ("Saving Grace"), Grace correctly and easily used the term pied-à-terre while showing her sample book to a potential client.
Character mistake: When Estelle gives her guest speech about the Tuskegee airmen she shows a slideshow. There is a photo of an airplane that she incorrectly labels as "a single engine P-47." This is not correct. The plane in the photo is a P-39 Airacobra. (00:19:45)
Character mistake: A "fetlock" is not a horse's hair; it's their ankle joint. If it was "blowing in the wind," the horse would be seriously injured.
Character mistake: Eddie, Spudgun and Dave Hedgehog all appear worried at the fact that the devil takes "virgin's blood." However, it is apparent later in the episode that the 'devil' is in fact Dave Hedgehog's daughter, meaning he isn't a virgin.
Suggested correction: Also, Eddie previously slept with the Third Viscountess of Moldavia when Richie's back alley kidney donation backfired and he collapsed, so he wasn't a virgin either, but reacted as though he was.
Although theoretically correct, bear in mind that neither Eddie or Dave Hedgehog aren't particularly bright, and likely forgot they weren't virgins.
Hedgehog's daughter could have been adopted.
Character mistake: Lucy Liu-bot says Fry's name normally, but uses an automaton voice for "Can eat more", when she has always used Fry's name as a Text-to-speech type of automaton voice. (00:07:45)
Character mistake: Dexter's father says he'll stunt jump over four school buses, but only three are shown.
Mine Your Own Business - S1-E4
Character mistake: When Shaggy and Scooby order Sarsaparilla at the saloon, Scooby says "Two" but he appears to be holding up three fingers.
Character mistake: When Mrs. Slocombe volunteers to sing while Captain Peacock plays piano, Mr. Humphries responds that he didn't know she could sing, even though the department staff has been involved in many musical numbers over the series.
Kiss My Bum - S4-E10
Character mistake: Before Ellen invites Perry to thanksgiving there was only going to be seven for thanksgiving and yet whenever someone is asked about how many there are going to be at thanksgiving they answer eight.
Character mistake: Mark walks into the house and is surprised to see Cody there, and remarks that he heard he was back. However, just before this, when Mark entered the house, Cody's van - which Mark had to walk by to enter the house - was visible through the open door, so that should have confirmed it for Mark before he saw Cody in person.
Timmy the Barbarian/No Substitute for Crazy - S5-E18
Character mistake: In 'No Substitute for Crazy", When Timmy and Sanjay are leaving the school after Mr. Crocker falls down the well, a few cats come up to them and he introduced an orange one as "Omar." Later, when Mrs. Sunshine is leaving after being substitute for a day, Sanjay has cats around him and comforts "Omar", except he says this to a red cat, not an orange cat.
Character mistake: When Matt is telling his Dad about his problems, he says "...I kicked our social studies globe last week by accent." He should have said accident; although this is not a major error it is worth noting and looking out for. (00:03:35)
The Blood of a Jeannie - S5-E7
Character mistake: Jeannie tells Tony that she can't blink, then immediately blinks.
The Hairy Scare of the Devil Bear - S1-E8
Character mistake: Velma says bears only have four claws. Wrong, they really do have five claws.
Character mistake: When Geoffrey serves tea after his sassy cough at Vivian's sentence about High Tea not being a sacred institution, the actor messes up when it's time to actually serve tea, with a napkin getting caught in the teacup saucer. Granted, accidents do happen, but it's quite uncharacteristic for the perfect butler Geoffrey is portrayed to be, and simply a flub by Joseph Marcell. (00:17:45)