Gavin, Colin, and Doug live on a cozy little drop of H2O until one day, their mother tells them it's time for them to grow up and leave home. In search of the perfect place to settle down, the three little tardigrades (also known as "moss piglets") journey to an underwater ice cave, an erupting volcano, and even the moon! They can survive under extreme conditions, but can they avoid the Big Hairy Wolf Spider?