Lots of the animals got their cash from, shall we say, slightly unusual owners.
Dr William Grier left £415,000 to his cats Hellcat and Brownie.
Thanks to careful investment, their children are minted moggies, worth £2 million each.
Kalu the chimp, at number two on the list, got his cash after owner Patricia removed her husband Frank O'Neill's name from her will.
Not that we're jealous, but what exactly did their owners think the beasties would spend the cash on?