Wikipedia on the chocolate fish: “The chocolate fish is a confectionery from New Zealand. These candies are fish-shaped, are 6 to 8 inches in length, and are made of pink or white marshmallow covered in a thin layer of milk chocolate. Several companies make the fish but the most well recognised is Cadbury, which makes foiled and unfoiled variants of the fish with a pink marshmallow centre. Smaller, or “fun-sized” variants of the chocolate fish are colloquially referred to as Sprats, the same name given to shoreline shoals of small fish. For a short period, in the late 1990s – early 2000, there was a Tip Top brand chocolate fish ice-cream that performed poorly in sales. Recently there have been suggestions of a return of this style of ice-cream in a new formula.
The chocolate fish has an important role in kiwi culture as a reward for a small job done well (“Give that boy a chocolate fish”). The term ‘invisible chocolate fish’ has also been a part of contemporary Kiwiana culture as a semi-sarcastic reward.”