Spar is a very, very strange creature. You meet him in the begining of the game, but never actually get him in your party until mid-way through. He is called "The Grassman" at a local Circus, until you rescue him much later. It is then revealed that he could've escaped any time that he wanted to, but was waiting for you. He can be a good addition due to his "Nature" command. But, it can only be done in outside areas.