Continuity mistake: When the scrunt forces his way through the door, it opens the wrong direction. The scrunt was inside the building trying to get out. When the latch broke, the door opened inward instead of outward, as if forced from the outside. How could the scrunt have done that?
Continuity mistake: When Reggie is fighting back the green beast he is standing in very short grass. In the next shot he hears the great eagle coming and he looks towards the sky. When he looks back at the beast he is standing in very high grass which was never near him.
Continuity mistake: When Cleveland is sitting on the sofa and waiting to hear the bedtime story, he eats a cookie and takes one sip of milk. At first he only gets some milk caught in his mustache, but in the next shot there's a lot more milk there.