Plot hole: How does the little girl Nina know Ferdinand's name if only the animals can communicate with each other? They're all calling him Ferdinand before she "names" him that.
Continuity mistake: Before the race in Thomasville Cruz has the 20 number only on her right side but later she has the number also on her left.
Continuity mistake: The amount of ketchup and mustard on the prison chef's apron changes between shots.
Continuity mistake: When Tim and the baby are tugging over the tablecloth, Tim's meal and drink have vanished from the table.
Continuity mistake: When they jump in the pool, they drop the guitar. When they jump out their guitar is no longer in the pool.
Continuity mistake: Gene and High Five are using costumes to hide, and Gene's costume leaves a spike in his face, but when they put the costumes down and run around the corner there is nothing on his face.
Other mistake: When Captain Underpants falls in the Turbo Toilet 2000's mouth which has a liquid in it, he doesn't turn into Mr. Krupp.
Continuity mistake: Gargamel finds out of the smurf he captured is Smurfette. She grabs the bars of the cage, but the position of the door hinges changes, switching from her right to her left, back and forth. (00:13:35)
Continuity mistake: Batman plans to put the Joker in the phantom zone, and Barbara says no. She is still right in front of the SUV, but in the next shot, she is suddenly standing more forwards.
Continuity mistake: Ray runs into his room to find Overgirl holding Red Tornado's cortex in her hand. A couple of shots later after she taunts him, she has her hands down at her sides with her fists balled and the cortex is missing. Only to appear in her hand again a couple of shots later for Ray to take. Her hand is too small, and the cortex too large for her to have simply just concealed it in her fist in the shot where it's missing. (00:50:40)
Continuity mistake: Sara recovers the artifact and gets on the boat. She removes the deep-dive helmet and the oxygen tank. The villain is looking at her through his binoculars, she hasn't moved, but the equipment she took off and dropped on the deck has vanished. (00:03:00)
Continuity mistake: When Mariah is talking to the girls on the bridge at the beginning of the movie, the girl in green is holding her leash (her dog's that is) with her right hand in the shots from behind, the left hand in others including the wider ones from the protagonist's height. (00:02:25)
Continuity mistake: In the mid-credits scene in Justice League vs. Teen Titans, Terra's hair was shoulder length and she had no freckles, but in this movie, she now has shorter hair and freckles.