Revealing mistake: When Jerry walks towards the crab with the soda bottle cap stuck on his head, one of the crab's legs disappears for a frame or two.
Salt Water Tabby (1947)
1 revealing mistake - chronological order
Directed by: William Hanna, Joseph Barbera
Continuity mistake: When Jerry produces a bucket of sand, he is not wearing his red swimming trunks, but when he replaces the sugar bowl with the bucket, he is wearing them again.