Continuity mistake: After their victory, the Turtles are celebrating and partying. Just before the episode ends, Leonardo is dancing on a white mat and doing the moon walk. It cuts to a higher angle and suddenly the white mat vanishes.
Left Behind - S3-E10
Continuity mistake: In the previous episode Ra's al Ghul stabs Oliver through his chest, just below his left pec. When he pulls out the sword, a wound is visible. (However, seconds later, the wound is absent - different mistake). In this episode he is shown with a wound much lower (in his lower abdomen) and also later, with a bandage around his waist instead of his chest. (00:09:30 - 00:41:30)
Continuity mistake: When Lin lifts the rocks around the house in the final scene, there are eleven of them. But in the last shot, there are only eight rocks.
Continuity mistake: From the flagpole, Spider-Man pins 2 goblin soldiers to the building and his web covers their torsos, including their shoulders and all the way up to under their chins. When it cuts to the close up, they're still stuck to the wall, but there's no web at all seen, even though we see their shoulders, necks, and chests.
Continuity mistake: Dio gets in front of Erina Pendleton that is heading back home. She spots him and her left-hand drops, but she again holds it high in front of her mouth in the next shot. (00:15:10)
Episode #2.4 - S2-E4
Continuity mistake: When Jacqueline raises a hand in response to her name being called, she puts up her left hand. A shot later, she has her right hand up instead.