Doof wasn't one of Jared's better Pokemon, which is why she was rarely used. However, Doof has had some moments of success. One of her biggest moments is sacrificing her life so that Daybo could be safely switched into. However, this is not what she was intended to do.
Doof died in the battle with Pokemon Trainer May on Route 110. Doof was switched out into because she was in perfect condition to fight. Things didn't go as planned however, and May's Combusken used Double Kick and hit Doof once, doing major damage, then Doof healed herself up a bit with an Oran Berry. After that, the Combusken had hit again, this time getting a crit., and killing Doof.