Porky wears a false beard when he is playing the wizard Merlin. But it disappears when he raises his arms to cast a spell for the second time.
After the Phantom of the Flickers reveals himself to be in black and white, his face alternates between green and gray in various shots.
When Sylvester was trying to cook a purple egg. Tweety's voice was sped-up.
Throughout the entire special Daffy had a high-pitched voice in the special.
When Porky & Yosemite Sam agree on catching the Phantom Porky's voice was slow & low-pitched.
When Sylvester finds himself surrounded by bulldogs, one of the dogs appears to be standing in the air against a tree rather than on the grass (misaligned background image)