Bloomburrow is a world where humans don't exist, but Mice, Rats, Frogs, Bats ... is the go-to Squirrel commander, and so it'd be a crime to not have him put in an appearance here.
There are a few reasons, but the biggest ones are: I love frogs, to the point ... The Fool is a very peculiar commander that came with Magic: The Gathering's Bloomburrow expansion.