Jim Possible and Tim Possible are Kim Possible's younger twin brothers, whom she affectionately calls the "Tweebs" (a portmanteau of "twin" and "dweebs"). They are distinguished by the color of the shirts they wear. Tim habitually wears red, while Jim often wears green. When they're not harassing Kim, they're making trouble with their next wacky science invention, launching rockets, or sending out screensavers of an unexpecting Kim to all of Middleton.