This is the prototype test robot for the ARL-99B.A smaller version of it's older brother this robot was entered into the SPRITE Arena by Shinohara to test it's hand to hand battle capabilities. After barely surviving a fight with Lien 'DIVER's circuits were shorted by unknown forces causing the crazy labor to go on a fighting rampage.
Shinohara has not been able to recover there prototype and are planning to send nbewer robots from the PATLABOR division to recover or even destroy the rampant prototype.