The Panzer

The Panzer is a weapon owned and used by Yamcha and Pu'ar. The Panzer is first used Chapter 10 - Onward to Fry-Pan.... It is used to first help in Yamcha and Pu'ar's attack against Goku, Bulma and Oolong in hope to steal their Dragon Balls. The attack involves Yamcha and Pu'ar using the Mighty Mouse, 

Automatic Rifle and The Panzer to attack Goku and company's vehicle and  to steal their Dragon Balls. The plan fails when Goku knocks out one of Yamcha's  and Yamcha and Pu'ar retreat. The Panzer is never used again.

Overview
The Panzer is based on a RPG.

The Panzer makes its only appearance in Chapter 10 used by Yamcha and Pu'ar to attack Goku for his

Dragon Ball. Yamcha uses The Panzer to damage the vehicle Goku and company were using, this forces Goku to exit the vehicle and fight Yamcha. As far as the series shows The Panzer is never used again. The Panzer is assumably left with the Mighty Mouse or left behind after the previously mentioned attack for the Dragon Balls.