The title is a play on the English meal, fish and chips.
Sylvester and his son watch a newsclip of Treg Brown catching a "sharp-nosed tralfaz". Junior says that Treg is a real fisherman. Sylvester asks what that remarks means, and Junior responds that they always end up eating beans after each fishing trip. To impress Junior, Sylvester takes his son fishing. Sylvester passes by the ocean, but declines fishing there, saying those fish take too much work. They break into a closed aquarium instead.
Sylvester goes up to a tank of piranhas. Unaware about the type of fish he is about to go after, Junior tries to intervene, but to no avail. Sylvester uses his tail as a fishing line, but gets bitten. "We wouldn't want them, they have no meat on them. Just teeth." Next, Sylvester freedives into a tank of groupers. As Sylvester is collecting some groupers, Junior realizes that there are hammerhead and shovelnose sharks in the tank. Sylvester looks into a hole the shovelnose shark makes, the hammerhead shark bangs him into the hole, and the shovelnose shark buries him. Junior reels his father out, but Sylvester pulls the rod out, telling him that he's the teacher, causing him to sink back into the tank.
Junior manages to catch a fish himself, but it is too small and Sylvester is not amused. Sylvester aims to catch a bigger fish using Junior's fish as bait, but is swallowed by a whale. Sylvester escapes the whale by starting a fire inside its mouth, causing him to be ejected into a dolphin tank and be tossed around like a basketball until he lands in a net.
Finally, Sylvester scuba dives into another tank to stab after fish. The fish hides inside a rock, and as he tries to grab it, he grabs an electric eel instead. He is clawed in the leg by a lobster and spanked by an octopus. Junior is distracted by a worm as he is cranking air for Sylvester, causing Sylvester to slowly suffocate. However, Junior realizes his mistake and rapidly pumps air into Sylvester's scuba suit, causing it to gain too much air and float up. Sylvester escapes via a hatch, but lands into another tank and is chased by dogfish. Junior sees his father and responds, "No matter what father tries to do, he always ends up going to the dogs", before shaking his head.