Transylvanian Homesick Blues - S2-E65
Character mistake: Ray says that it's the very first time they've dealt with vampires. In Season 2 Episode 25, "No One Comes to Lupusville", the Ghostbusters had to deal with both werewolves and vampires.
Character mistake: At one point in the show, Roger throws a bucket of water (in disguise as Scotch Bingeington) on Francine claiming "Wet T-Shirt Contest!" Francine looks disgusted when Roger states "Eh, give this one a four" to the guy judging the contest, then says to Francine "Don't feel bad, you've had three kids." Francine replies "I've had two." and Roger gasps and puts a consoling hand on Francine's shoulder. This is wrong because Francine has birthed four children. She previously gave birth to Bailey (Hayley's twin), and Greg and Terry's baby in Season 3 Episode 7 "Surro-Gate." (00:14:15)
Character mistake: Brock states that the Diglett are plowing the ground and the Dugtrio are planting the trees, but the opposite is true (The Dugtrio are plowing, and the Diglett are planting).
Tenacle-vision/I Heart Dancing - S7-E8
Character mistake: In "I Heart Dancing", the lady at the Krusty Krab tells Spongebob the dancing audition is the next day. Later, Spongebob is practicing at Squidward's house for a whole night, and the next morning Squidward says they have one more day to practice, even though the audition should have been that day.
Suggested correction: The audition could have been during the afternoon.
Character mistake: Throughout the entire series, the Turtles are referred to, by others and by themselves, as amphibians. But turtles are reptiles, not amphibians. However they are amphibious, amphibious reptiles.
Character mistake: The narrator says, "some trucks were left behind", but only 1 truck was left behind.
Character mistake: When all the wives are in the van Lois calls Bonnie "Debbie".
Homer Badman - S6-E9
Character mistake: When Grandpa is putting up the American flag for Homer's public access show and Marge says the flag only has 49 stars, there are actually only 38: 8+7+8+7+8.
Simpsons Already Did It - S6-E7
Character mistake: Butters says that he watched "all 132 episodes" of the Simpsons; at the time this episode aired, 291 episodes of the Simpsons had been produced and aired.
Suggested correction: Butters is always shown as being a bit dim and slow. As a kid it's easy for him to make a mistake in thinking that there was only 132 episodes.
That's why it's called a "character mistake"; also, Butters is certainly naive, but he's hardly what I would call "dim and slow."
Just Stuck It in That There Doo-Dad - S3-E3
Character mistake: At the start of the episode, Jimmy says he met Cookie at work. The scene then changes to the strip club where Cookie is working and Jimmy is there looking for Bobby. In the Season 1 episode "The Horny Bastard", Jimmy tells Cookie that they met when he robbed her dad's liquor store.
Well Bargained and Done - S1-E2
Character mistake: Tybus says he has a lance of 5 mechs. In Battletech, a lance is 4 mechs. While a Clan star does have 5 mechs, Tybus is an Inner Sphere character.
Character mistake: When Jet tells Katara and Aang to waterbend the water from underground in the geysers, Katara states that she has never waterbent on water she couldn't see before. However, six episodes prior to this, in 'The Warriors of Kyoshi', she waterbends the water out from Aang's lungs to save his life.
Suggested correction: That was a moment of desperation on her part, and she probably doesn't think of it/think she can do it again without the same desperate impetus, Furthermore, the water in Aang was only a small amount and very close anyway.
Regardless of if she did it in desperation or not, she did use bending on water she didn't see. The mistake isn't suggesting anything about Katara's ability to waterbend unseen water, the mistake is only in regards to the statement Katara made about never using bending on water she can't see. And for Katara to forget the one time she used bending on water she didn't see would qualify as a character mistake as well. Now if she made the statement "I don't think I can do this" or "I've never used bending on underground water", etc, that would not be a character mistake.
Character mistake: Hank talks about watching the Broncos vs the Cowboys in Super Bowl XIII. This is incorrect. They played in Super Bowl XII. Super Bowl XIII was the Cowboys vs the Steelers.
Origin of Iron Man: Part 1 - S1-E11
Character mistake: When young Tony Stark is telling his father that their helicopter's anti-flak chip didn't kick in, he acknowledges that it was his fault by saying he blew it. When his father corrects him and says "No Tony, we blew it. Stark and Son," Tony defensively says "The anti-flak chip failed, it's not my fault," completely contradicting what he said seconds earlier. (00:14:00)
Character mistake: Tai says "And it started to snow in the middle of July" but later you find out that it takes place on August first.
Character mistake: The math test Tina gets a D on has #5 marked wrong. However it is correct. (Additionally it seems improbable she would actually get #3 and #4 wrong since she obviously understood the concept of how to do the problem and only had a problem with the division for some reason, and these questions didn't require division).
Harder, Better, Faster, Browner - S2-E1
Character mistake: 21 seconds pass between the time they start to write a song and Kenny says "Done". Cleveland then says it was 15 seconds when it was 21 seconds. (00:11:05)
Character mistake: In the map of South America, the nation of Chile is misspelled as "CHLIE." (00:18:05)
Character mistake: Another identity mistake in the finale: When Beast Boy's team is initially subdued, we see honorary Titan Hot Spot standing amongst the villains even though he is a) a hero and b) is supposed to be frozen solid at that time.
The Calculus Affair: Part 2 - S1-E13
Character mistake: After reaching the border, Snowy finds an umbrella and Tintin states that it is Calculus's umbrella. It isn't Calculus's umbrella - Calculus's umbrella has a brown handle, and this one has a grey handle. (00:42:25)