A painting that uses popular cartoon characters to parody Leonardo da Vinci’s “The Last Supper” is causing a bit of a stir in Old Town San Diego. “The Gathering,” a new painting by artist Glen Tarnowski, uses Looney Tunes characters such as Bugs Bunny, Daffy Duck, Marvin the Martian and Road Runner to stand in for Jesus and his disciples in da Vinci’s famous 15th century fresco.