Mitchell had a Pokemon battle with his older sister in which she defeated his Murkrow fairly easily. He didn't like the fact that he was defeated so easily and got mad at his sister and ran off.
Mitchell began practicing with his Murkrow by throwing things at it to help it deflect things. Unknowingly, he began to throw more and more at his Murkrow until it was unable to deflect the incoming rocks and got hurt. Murkrow got mad and flew off.
Team Rocket showed up and tried to take the Dusk Stone and his sister's Misdreavus. Mitchell made up with his Murkrow and asked it to help save his sister and her Misdreavus. It agreed and was able to help defeat Team Rocket. After his sister was rescued, Mitchell made up and apologized to his sister.
The character's Japanese name is taken from the character of the same name in Maurice Maeterlinck's The Blue Bird, which his episode was heavily based on.