The Whirly Dirly Conspiracy - S3-E5
Continuity mistake: When Beth glues the horse hoof on, the bottom is facing up. In the next shot it facing to the side. And then the leg changes shape in different shots.
Continuity mistake: When Steven arrives on the Sun Incinerator, he's carrying a large sub (sandwich), which he gives to Lars. After the ship's power goes out shortly thereafter, the sub has vanished.
Continuity mistake: Sometimes Cyborg is waterproof and sometimes he isn't.
Surf'N Turf/Hardcase Returns - S1-E8
Revealing mistake: In "Hardcase Returns" Skidmark uses a digital phone to track a GPS device installed on Turbo's parade car. When the keypad on it is shown, 3 letters are missing. They could have been on the keys that had nothing written on them, but we will never know for sure because nothing is on them.