Clasko is a young man who served as a Chocobo Knight before the Eternal Calm, retiring shortly after the massacre of Operation Mi'ihen. Clasko never felt comfortable in his position. Although he was was good at taking care of the chocobos, he did not find himself comfortable with the strict pace maintained by Captain Lucil.
Tidus first meets Clasko, at the Mi'ihen Highroad alongside Lucil and Elma and again at Djose Temple and the Moonflow. He begins to question what he should do with his life. Outside the travel agency at Lake Macalania, he asks Tidus for his opinion on what he should do. Based on the player's decision, Clasko would choose to either remain a Chocobo Knight or become a chocobo breeder. If the player chose the "chocobo breeder" option, they could later find (after gaining airship) that he had become the keeper for the chocobos on the S.S. Liki. He says that Elma was upset with him, but Lucil understood and gives the player a Friend Sphere he discovered in one of the chocobo nests.