Which episode of the Simpsons featured Willie fighting an Alaskan Timber Wolf?

As I recall, the episode started with an animal show-and-tell type thing on the Krusty show. They bring out the wolf, the children start screaming because the handler said the word of the day, and the wolf goes berserk, which almost leads to Bart being mauled, save for the timely arrival of Groundskeeper Willie. So, which episode is that?