A knickerbocker glory is an ice cream sundae that is served in a large tall glass, particularly in the United Kingdom. There is no precise recipe, it can contain a wide variety of ingredients including: ice cream, jelly, cream, meringue, fruit, and even alcohol. It can then be topped with various kinds of syrup, nuts, whipped cream and cherries. On Dudley Dursley's birthday in 1991, while at the Zoo, Dudley ordered one of these after lunch, but threw a tantrum that it did not have enough icecream on top. So his father ordered him another one and gave the rest of the first one to Harry.