The worm sports the rectangular appearance the est of the animals have. It is brown with a lighter brown square on its neck, and is the smallest entity in the game.
As the Worm: Use your burrowing ability to hide from predators, although they usually have no interest in you. You have no boosts, so be very careful.
Against the Worm: The worm is an insignificant threat. It does little damage and has low health. Worms are at your mercy.