Continuity mistake: Watch the small bed inside the water tower. Soon after the song 'Somewhere Out There', a small piece of cloth appears from nowhere on it. (00:41:10 - 00:43:15)
Continuity mistake: During the rally at Mausheimer Park, Fievel steps up to the podium and whispers a plan into Gussie's megaphone. When Honest John asks to hear it, Gussie can be seen holding the megaphone's handle with three fingers as she speaks to him. But once the shot changes, she suddenly has only two fingers on the handle. (00:45:20)
Continuity mistake: When Fievel is running after Tony in the back alley, he gets stuck in a sewer grate hole and hears what he thinks is Papa's violin coming from down below. Throughout the scene at some points, Fievel instantly appears in different grate holes. (00:48:20)
Continuity mistake: When Fievel is making his way through the sewer looking for Papa, he enters the Mott Street Maulers' hideout where five cats are seen playing poker. The gray cat with a blue shirt is sitting on the carpet's edge, but in the next shot he's somewhere towards the middle instead. (00:49:25)
Continuity mistake: In the scene where Fievel walks in on a group of cats playing cards, Tiger slaps down his hand and yells "Rummy!" But once he gathers the cards and holds them up again, there's a 3 of Diamonds visible - which wasn't part of the original hand to begin with. (00:50:00)
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: 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: 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: When Fievel discovers that Warren T. Rat is actually a cat in disguise, the hat tucked into his black belt disappears between shots. (00:51:20)
Continuity mistake: When Warren T. Rat grabs Fievel from behind the glass, his hand has a grip around Fievel's blue pants at first. But as soon as the shot changes, Warren T.'s hand is gripping bare ankle instead. (00:51:25)
Continuity mistake: After Fievel sinks his teeth into Warren T. Rat's left arm from behind a mirror, he howls in pain. In this shot, the reflection of Warren T.'s teeth isn't reversed like it should be. (00:51:25)
Continuity mistake: When Tiger and his pals are tearing apart the poker table in search of Fievel, watch the lower right corner of your screen. At some point during the commotion, one cat drops his gray hat and it vanishes into thin air. (00:51:35)
Continuity mistake: When Fievel is struggling to avoid the other cats on the player piano, Tiger appears on its right side and pounds the keys, just missing him. But Tiger instantly disappears from his location in the very next shot where Fievel jumps up to the music rolls. (00:51:55)
Continuity mistake: In the sewer where Fievel is trying to evade the cats - at the point where he's on a roller skate heading downhill into the path of a live bear trap - several notches on the skate's belt disappear between shots. (00:52:10)
Continuity mistake: When Gussie is demonstrating a secret weapon plan for the other mice, she points to a world map, pushing a small wooden boat from the end of a dock all the way to Hong Kong and leaves it there for the remainder of her speech. After she's finished Gussie dismisses the mice, but now the boat has returned itself to the original location on the map. (00:53:20)
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 "A Duo", Tiger picks up Fievel's cage and places it on a nearby step. Between shots, the cage tray decreases in size significantly (judging by the overhang). (00:56:35)
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: When Tiger and Fievel are doing their musical piece, Tiger wipes off the mirror and they appear the same size. When he lays out in front of the mirror, singing the line "We'll be there to pick each other off the floor", he places his head next to the cage bottom, still laying on the floor between them. In the mirror, however, that cage bottom is not reflected at all. (00:57:30)
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)
Answer: Warren T. grabbed Tiger and told him he was fired.Tiger did eventually leave some time after that though.