Bass

Dr. Wily created Bass, who first appeared as an intro-level boss in Mega Man 7 Bass has alway's had a vendetta against Mega Man, most likely because Dr.Wily programmed him that way. For reasons unknown, Bass had turned against Wily in Rockman & Forte (aka Mega Man and Bass, though it's possible that Bass was unaware that King was under the employ of Wily. One of the most common disputes concerning Bass is about the pronunciation of his name; despite the fact that Mega Man 8's voice clips pronounce the name like the fish, the generally accepted pronunciation is like the musical term (which is also supported by the fact that his dog is called Treble in English releases, which makes a very nice musical pun).  He appears as a playable character in both of the arcade games (The Power Fighters and The Power Battles).  His weakness in Mega Man 7 is either your standard Mega Buster (because it's all you have at the time) or possibly if you have a Rush Adaptor. A good general strategy is, as always, to charge your shots, dodge his fire as best you can, and then unload your blaster on him.