DrillMan.EXE

DrillMan.EXE is a solo Navi that tries to sabotage a small company working with BlazeQuest.

DrillMan.EXE was revived as an Asteroid Navi by Duo and given to Rat by Slur.EXE, who overwrote Rat's NormalNavi with DrillMan.

(Source: The Mega Man Knowledge Base)