The Honking - S3-E1
Continuity mistake: When the two guys are smashing the cab there is a bunch of magazines lying on the ground. When it cuts to Bender's point of view of the guys the magazines are gone. (00:08:10)
The Honking - S3-E1
Revealing mistake: In the final battle, Bender has fry trapped into the seat inside of him, and he drives over a ramp and nearly smashes into the original were-car mid-air. But when the were-car lands on the same ramp that Bender took off from, we see that the furnace is literally touching the end of the ramp. How did Bender get up enough speed to launch himself into the air, especially accidentally (he would have had to turn 90 degrees to get onto the ramp) with the furnace that close? Also at the start of this scene, we see the were-car crying in front of the furnace, and the ramp is nowhere to be seen. (00:19:50)
The Honking - S3-E1
Audio problem: When Leela welds Bender to the wall, she uses a gas torch. The sound effect is that of an electric arc-welder.
Continuity mistake: In the episode "Mars University" we are shown how robots in "Futurama" attend a regular college, alongside humans and other species, over a periode of at least one college semester. Bender even talks about how he attended and majored in bending (minoring in Robo-American history). However, in this episode, we are shown that his entire "education" consisted of downloading a file at the factory where he was made. There is a clear inconsistency in these two stories of Bender's education.
Time Keeps on Slipping - S3-E14
Continuity mistake: After the end of the basketball game, Leela's tights briefly disappear. (00:07:35)
The Honking - S3-E1
Continuity mistake: When they find Bender on the ground after being hit by the were-car Fry asks if any of them have any liquor you see all of them reaching out a bottle of liquor. When Bender grabs one of the bottles it cuts and you see all of them standing back as if none of them were handing him anything. (00:06:25)
Continuity mistake: When Cylon and Garfunkel are singing "Scarborough Fair" note that when you see them from the front there is one microphone, but when viewed from behind there are two.
The Day the Earth Stood Stupid - S3-E7
Continuity mistake: When Nibbler closes the door to the spaceship you see some of Leela's hair stick out. When it cuts her hair is gone. Then later it appear again. (00:06:50)
The Cyber House Rules - S3-E11
Continuity mistake: When the doctor removes the bandages round Leela's head, Hermes and Amy change position.
Continuity mistake: When the pizza box says it's only been 23 minutes the face on it smiles with its mouth closed. When it cuts to Fry talking the face is smiling with its mouth open. (00:06:50)
Continuity mistake: During the chase after the concert we see Beck's tour bus in the mirror of the Combi. The word Beck in the front of the bus is the right way around. It should be reversed. (It is the right way around in other shots). (00:19:30)
The Cyber House Rules - S3-E11
Continuity mistake: In the scene where Leela and the doctor are driving out of town and throughout the episode Leela's second eye is following her motion. This despite the fact that in a previous scene we could see that she was unable to move her second eye. (00:09:55 - 00:12:00)
The Cyber House Rules - S3-E11
Continuity mistake: When Bender and Fry leave the kids' room, Bender shuts the sliding door closed. When he's calculating how much he's making, the door is open.
Continuity mistake: The way Professor Farnsworth holds Leela's jacket changes as he goes to give it to Fry and then Bender. He's holding it from the back at first, but in some shots he's holding it from the front. It changes in Bender's hands too from back to front.
The Day the Earth Stood Stupid - S3-E7
Continuity mistake: When Nibbler bites the balloon and goes flying up, you can see there's a big open space between the "cream" booth and the "soylent chow" booth. And there's no curtain partition behind the booths. When he lands, the booths are right next to each other and you see the curtain.
Amazon Women in the Mood - S3-E5
Continuity mistake: As Zoidberg goes to toss his old shell in the dumpster, there is a crack down the back. In a previous shot, we see the back of him for a second and there is no tear in his shell.
The Honking - S3-E1
Continuity mistake: At the end, the Were-car skids sideways and flips into the furnace. From the outside, it lands upside down in the furnace. A second later, it's right side up.
Continuity mistake: When Fry and the kid are racing along the motorway, just after they let go of the cars they are holding onto, they head into a lamp post. This leads them to banging their heads and collapsing on the floor, because the ribbon they were holding onto forces them into the lamp post. When they fall on the floor, the dust shoots up. After the dust disappears, the lamp post has as well, meaning that the ribbon isn't actually tied around anything.
Continuity mistake: When Bender enters the officer's bar, he has two medals on his chest. In the last shot of him they have both disappeared.
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)
Answer: You are thinking about episode 20 of series 2 - "Anthology of Interest I". She technically never kills anyone, but in the episode she ask a "What if machine" (one of the Professor's inventions) what would happen if she was more impulsive. The machine then shows the more impulsive Leela killing off the Professor to get the money from his will and thereafter killing Hermes, Bender, Scruffy, Cubert, Nibler, Amy and Zoidberg to cover it up. Finally she does something really impulsive with Fry.
Andreas[DK]