Shock Therapist

The Shock Therapist is actually a Crookes Tube with circuitry undneath in Pikmin 2. It is found on the 14th sublevel of the Dream Den, and is held by the Titan Dweevil and serves as one of its four weapons. It must be knocked off by dealing enough damage to the part. It is able to produce electric discharges that will kill any Pikmin other than the Yellow ones. It is the 197th treasure on the List of Pikmin 2 treasures.

Captain Olimar's Journal
"This shocker was one of several weapons wielded by the nightmarish titan dweevil. It allowed the creature to smite Pikmin with zaps of lightning!"

Sales Pitch
"This nanotech device gathers negative ions in the atmosphere and converts them into energy. It then releases that energy. Zap! Use it to relieve muscle soreness and joint stress. One warning, however: it does render the user unconscious."

Trivia

 * This is one of the five treasures that are tied for second in their value.