The Research Combatant was a type of battle droid created by the Gray Secant, a Gree research starship, for the purpose of testing the combat capabilities of sentient lifeforms at the Gray Secant's research pylons. The large, three-legged droid came in two identical variations—Mk-II and the more powerful Mk-IV. When the pylons were activated, the Gray Secant would dispatch a trio of Research Combatants, Research Probes, or Research Battlers to that pylon.