Bass

Bass known as Forte Forute? in Japan is a Robot Master created by Dr. Wily to imitate Mega Mans design along with Treble an imitation of Rushs design. He was created sometime during or before the events of Mega Man 6 and made his debut in Mega Man 7. Bass is the prominent antihero of the Mega Man classic series fighting against Mega Man to prove he is the strongest robot in existence. Although Bass and Mega Man are rivals at times they team up to take down mutual enemies of the two. Through these teamups with Mega Man and his friends and their plea for peace and friendship Bass seems to become less hostile to them as time goes on. Source: The Mega Man Knowledge Base Wikia