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.
Weirdmageddon: Part 1 - S2-E18
Continuity mistake: Two guys are throwing a frisbee and it lands on the ground. In the next shot, the frisbee is gone.
Nightmare on Christmas - S3-E22
Continuity mistake: When Power Man is wearing White Tiger's tiara (her Christmas gift), he has it on point-side down. White Tiger grabs it with both hands and puts it on and it's now point-side up, without her flipping it. You also see it go from a partial band tiara to a fully enclosed band tiara, like a crown.
Continuity mistake: When JoJo is eating the steak the first time, in close-up the juices have overflown the plate, but in the next shot there's no such mess on the tablecloth. Moreover, you can see him cut the last piece in half, and then pick it up whole. (00:02:50)
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.