Continuity mistake: As Fievel is gazing into the barrel of herring, an apple core falls in. The apple casts no reflection as it falls into the water, whereas Fievel's shadow is visible. (00:10:25)
Continuity mistake: In the scene where Tiger and his friends are playing poker at a round table, the leader (who says "Ante up, boys") is seen wearing a different colored shirt between shots. At first it's purple, but in the close-up shot it briefly changes over to black. (00:50:25)
Continuity mistake: In the opening verse of "There Are No Cats in America," Papa finishes telling his story and an elderly mouse faints, dropping her sewing needles and yarn to the floor. But when the chorus begins in the following shot, she's suddenly holding them again. (00:12:10)
Continuity mistake: In the initial scene where Papa is handing out Hanukkah gifts, he gives Fievel a family heirloom: his blue hat. But as Papa drops the hat onto Fievel's head, the direction of its bill changes between shots. (00:04:15)
Continuity mistake: Before Digit jumps out from Warren T. Rat's pocket, he pushes out all kinds of accessories such as pencils and playing cards. But when Warren T. looks in the mirror trying to figure out how to make an extra fifty cents, the items reappear - sticking out of his pocket again. (00:25:20)
Continuity mistake: Throughout the entire scene involving Fievel being locked in a cage and singing "A Duo" along with Tiger, his blue hat is nowhere to be found. But after the floor mirror's glass shatters, he and Tiger are locked in a handshake and, all of a sudden, the hat is now tucked under his belt. (00:58:30)
Continuity mistake: After Gussie outlines a secret weapon plan to get rid of the cats, she walks over to the clock and moves its hands to 6:00. But right before the scene ends, the hands are positioned at 5:00 instead. (00:53:40)
Continuity mistake: During the storm, Fievel makes his way to the staircase and climbs a rope onto the fourth step. Suddenly a torrent of water rushes in from the deck above, forcing him to take cover. When Fievel emerges to look at some washed-up fish down on the floor below, the rope is nowhere to be seen - but it soon reappears a few shots later when Papa chases after him. (00:16:05)
Continuity mistake: When Warren T. Rat leads Fievel to the door of a tailor shop where his family is supposedly located, its hinges vanish right after Fievel jumps into the elevator. (00:27:45)
Continuity mistake: In the opening scene where Tanya and Fievel receive their Hanukkah gifts, Papa can be seen tying on a new headscarf for Tanya in front of a mirror. When Tanya turns around to admire it in the following shot, Papa's hands are still working but his reflection isn't visible in the mirror. (00:03:50)
Continuity mistake: When Warren T. Rat is playing the violin off-key, he hits a bad note and blames his fake nose for getting in the way. With the bow still in hand, Warren grabs his nose and proceeds to twist it off. But the bow vanishes in the next shot as his nose snaps free. (00:50:50)
Continuity mistake: In the opening shot of Mickey O'Hare's wake, the wooden door is visible with hinges attached on its right side. Pretty soon Gussie makes her entrance looking for Honest John, but now the hinges have switched sides. (00:38:00)
Continuity mistake: After Gussie Mausheimer walks out of Mickey O'Hare's wake, Bridget asks to speak with Honest John regarding Fievel's family. Pay attention to the attendees in the background who are gathered around Mickey's picture: they keep disappearing in every other shot throughout the remainder of the scene. (00:40:20)
Continuity mistake: When Fievel is curiously wandering around below the ship's deck he discovers three barrels of herring, each one of which is specifically marked for breakfast, lunch and dinner (dinner being closest to the staircase). A little while later, Fievel is being tossed around on a bar of soap that carries him back to the barrels of herring. But when he lands on the dinner barrel, it's now marked as breakfast instead. (00:10:15 - 00:16:00)
Continuity mistake: During "A Duo," Fievel is standing on a cage tray which Tiger slides next to a dirty floor mirror. Once Tiger begins singing the chorus, the tray disappears - only to reappear in its original location once Fievel wipes the mirror clean in the next shot. (00:57:05)
Continuity mistake: After Fievel gets captured by Warren T. Rat, he's ordered to work alongside numerous other mice in a tailor shop. In the following scene where everybody's asleep, Fievel jumps from his bed and walks over to the nearest window - making a reference to Rapunzel's hair and how well it would work to escape with. All of a sudden, two long white sheets conveniently appear on the floor behind him out of nowhere, from which he makes a long rope to rappel down the side of the building (not unlike Rapunzel's hair). (00:28:50)
Continuity mistake: During Mickey O'Hare's wake, Gussie Mausheimer opens the door and starts talking to Honest John about organizing a rally to help get rid of the dangerous cats. But during her last sentence regarding uptown mice, notice how the door has vanished. (00:40:00)
Continuity mistake: When Warren T. Rat is near the museum's entrance trying to negotiate with Gussie, he's wearing his purple nightcap and a rat disguise. But Tony's not convinced he's really a rat, so he sets out to expose Warren T. by firing his slingshot. In the following shot part of Warren T.'s disguise falls off as planned, but he's now holding the nightcap instead of wearing it. After replacing the nightcap he tries to explain his way out of the situation, but once again in the very next shot where Tony takes aim to fire a second time, he's suddenly shown holding the nightcap. (01:00:30)
Continuity mistake: When Warren T. Rat is playing his violin off-key, there's a female statue behind him adorned with candles, and at first glance it seems to be in good condition. But after Fievel witnesses Warren T. shedding his rat disguise, the statue is now significantly cracked in many places. (00:50:40)
Continuity mistake: During Mickey O'Hare's wake, Honest John's shot glass refills itself between shots, at the point where he asks Gussie Mausheimer, "What's a wawwy?" (00:39:40)
Answer: Warren T. grabbed Tiger and told him he was fired.Tiger did eventually leave some time after that though.