I found Squirrel Eat Squirrel in Making Games with Python and Pygame by Al Sweigart. He described it as loosely based on 'Katamari Damacy'. You are squirrel who eats smaller squirrel which makes you bigger until you reach omega squirrel. I really liked the game despite it's simplicity. I decided to modify it to have better graphics and different type of squirrels. The different squirrel types don't have any gameplay effect at the moment.
Squirrel Eat Squirrel Github