Factual error: The "Great Terror" turns out to be a giant goose, but you see in the shot inside the castle that its footprint is not webbed, even though geese have webbed feet.
Factual error: Johnny's dad and gang come to over protection services to Moon and the singers. Despite almost no time having passed since the first Sing movie, as evidenced by Rosita's children having not aged, the gang appear to have been released from prison. The gang were in for armed robbery and at least one case of escaping prison. The minimum terms for those charges would keep them in prison for years.
Factual error: Milo says Audrey is a "teenager". Which she is, but this is 1914! People didn't use that word back then. He probably should have said "adolescent" or something.
Factual error: While Ferdinand and the bulls are running free in Madrid they pass by the Puerta de Alcalá monument with a set of three columns and a door in the middle. The drawing is actually missing two huge blocks with 2 doors on each side.
Factual error: With a number of flowers blooming, the movie appears take place in spring. There are many scenes of central park with flowering trees and shrubs in full bloom. However, the yellow blooming shrubs called forsythia do not bloom at the same time as the flowering cherry trees. Forsythias bloom about a month earlier than cherries and are usually the first items to bloom in spring.
Factual error: The alligator mentions wanting a Bananas Foster. This dessert was invented in 1951 but this movie takes place in 1926.
Factual error: The unit on Dusty's torque dial appears as FT/LB (i.e., FT divided by LB) which is incorrect. FT.LB (i.e., FT times LB) is a unit of torque.
Factual error: The police are circling the theatre to find out where Johnny's escaped father is. During this, you can see that Mike is getting pulled upwards towards the copters like a piece of metal getting attracted to a magnet. Helicopters create downdrafts - Mike should've been blown away from the stage rather than being pulled up.
Factual error: The USA map is inaccurate for the year it is set in. It shows all states but in 1886, many of the northwest states (e.g. Montana, Idaho, the Dakotas) weren't states until 1889+.
Factual error: Parker is looking for the phone her mom hid. She is moving a box of cereals. The cereal ingredient label has a few joke entries you may Miss at first (goat hair, bitter almond paste, false eyelashes), but the nutrition facts tab is also incoherent in a way too subtle to be a deliberate joke; sub-categories of each macronutrients exceed the total. For instance, it has 5 g of Fat in total, but 25 g of Cholesterol and 56 g of Saturated fat (at most it could be mg). (01:00:25)
Factual error: The rabbits are underneath the landrover, and they get shot out the back whilst holding on to the axle. Land rovers have an enclosed axle with a hub enclosing the diff, so this would not be possible.
Factual error: When Dark Superman begins X-Raying himself in the mirror at the salon, the reflection is not a mirror image, as his hair curl is still on the same side. (00:53:10)
Factual error: The term mayor of Paris was abolished from 1871 till 1977. But we see Victor Maynott wants to join the mayor campaign in 1910.
Factual error: In the timelapse footage showing the street outside Bob's Restaurant, the shadows are moving in the wrong direction. In the northern hemisphere, shadows go clockwise. (00:13:46)
Factual error: As Danny arrives in Hollywood at the beginning of the film, the Hollywood sign can be seen. The film is set in 1939 so the sign should still read Hollywoodland, as it did until 1949. (00:03:00)
Factual error: When New Island's reflection is in a window on Giovanni's helicopter, it is not reversed. (00:15:19)
Factual error: Metrocity appears to be located in Michigan, but the news station on the truck starts with K, which signifies that's it's in the western half of the US.
Factual error: The average Iguanodon is estimated to have weighed around 3.4 tons, while Carnotaurus probably weighed about 1.5 tons. By this logic, during the final Carnotaurus encounter, the rocks at the edge of the cliff should have crumbled when Kron tried to escape, but remained intact until the Carnotaur was at the edge of the cliff. This is because the Carnotaurs in the film are inaccurately depicted as being T-Rex - sized animals.
Factual error: Spongebob and Plankton are told to supervise the universe for Bubbles while he goes on a bathroom break, this result in Jupiter and Saturn colliding with each other. Saturn is depicted as much smaller in relation to Jupiter than it is in reality. Also, the effect of their collision is inaccurate since both planets are mainly made up of gas. (00:44:50)
Factual error: During the bike chase towards the end, as Cloud and Loz/Yazoo crash through the security gate, you can see that the lettering is misspelled: "Authorized Parsonnel Only." It should read "Authorized Personnel Only."