Viridian is a free print-and-play, roll and write game that has armies of animals defending their forest against invading humans. Technically, it’s a flip and write, where you flip cards for an outcome and then make decisions about what spaces to mark on your scorecard.
The game’s cover illustration has a grizzly with a turret gun strapped to its back. How can you go wrong.
Source: miniaturewargaming.com