Grandpa is determined to beat Billy "Strike" Maxwell, his long-time challenger who ensures his victory by having the game rigged. The Rugrats, looking for the "chocolate chip" (championship) and the "big candy dish" (bowling trophies), inadvertently expose the fraud.

Playing doctor (not THAT kind of playing doctor) with her ""Binks McGill"" doctor kit (based on the TV show), Angelica diagnoses Chuckie with the entirely ficticious ""Rhinoceritis"", in which Chuckie will turn into a rhino. The signs of ""Rhinoceritis"" includes a bump on a head (where ""a horn is growing in""), scaly skin (actually, scabs), and ornery behavior. Meanwhile, Drew helps Stu and Didi with their income tax, with some sound advice for those who don't file properly.

Angelica finds a nickel in the sand box and thinks there's a fortune under the sand, so the babies dig. They start arguing about finding more nickels. Angelica maks the nickel with an X, but the wind blows it away and Angelica digs frantically to find it again. The babies don't care about nickels anymore and they just play happily again.

Charlotte brings Tommy and Angelica to her office building where, while Charlotte makes a deal with the Famous Ethel cookie factory, Tommy and Angelica wreak havoc in the office by damaging plans for the Cookieland theme park and breking Jonathan's fish aquarium.