Well, 'The Wind in the Willows' is a wonderful adventure animal fiction novel. It focuses on the lives of Mole, Rat, Toad, and Badger. Their adventures along the river and in the Wild Wood are really charming. 'Redwall' by Brian Jacques is also great. It's set in a world of anthropomorphic animals and is full of battles, quests, and friendships. 'Animal Farm' by George Orwell can also be considered in a way. It's an allegory with animals representing different human types in a political and social adventure on the farm.
One of the top adventure animal fiction novels is 'The Call of the Wild' by Jack London. It tells the story of a dog named Buck who is thrust into the wilds of the Yukon during the Klondike Gold Rush. Another great one is 'Charlotte's Web' which features the friendship between a pig named Wilbur and a spider named Charlotte on a farm. And 'Watership Down' is also highly regarded, following a group of rabbits on their perilous journey to find a new home.