Proto Man was
Mega Man's brother. Or something. He is always dressed in
red, and can be identified by that thing hanging off the back of his head, which is either a
ponytail or a
bandana. He first appeared as a
shadowy,
enigmatic sentinel in
Mega Man 3; periodically throughout the game he would
drop in, play the
flute for a minute or so, fight you for a little while, and then suddenly open the way to go on and drop back out. He never fought very hard; all he did was jump around and shoot
pellets at you, and you could just
slide right under him. Nothing ever seemed to
hurt or affect him in any way. I'm not totally sure why he was fighting you; i think he was supposed to have been
testing you, or helping you
train or something. But you didn't know that at the time-- at the time it was just
confusing, and you had no idea what was going on with him. After you beat the first block of
levels in MM3, you were suddenly presented with a level labelled "Proto Man", which consisted of nothing more than a twenty-second fight with Protoman.
That didn't make things any more clear, but at least at that point you knew his name. At the end of the game, Proto Man was revealed to be a
good guy with connections to
Dr. Light and stuff, and at the end of the
final boss he suddenly drops in out of nowhere, rescues you from death, and finishes off the boss.
So in the end you're supposed to be grateful to Proto Man and think of him as a good guy even though he was fighting you, or something, but the whole thing still seemed kind of suspicious; the thing is, since Proto Man was obviously far stronger than Mega Man, and seemed to be able to teleport anywhere at will (Mega Man could only teleport to the beginning of the level), how come he wasn't the one out there fighting Dr. Wily in the first place? It was never made clear why Proto Man didn't just teleport directly to each boss room, do his hopping-around thing while the boss tried in vain to damage Proto-man's indestructible body, and then 0\VN the boss with his 31337 flute-playing 5k1LLz. Either i missed some plot element that explained it, or this is just a striking example of Nintendo Logic. Either way something suspicious was going on, judging from the later games. Proto Man was conspicuously absent from Mega Man 4, but when you finally got to the end of the final boss Proto Man once again comes in and saves you and finishes the boss off-- only does it in such a way that it seemed to have been heavily implying that Proto Man had been at one point working for Dr. Wily as some kind of double agent, and then suddenly turned on Wily at the end of MM4. Things get even more confusing in Mega Man 5, where proto man is actually the evil power you're fighting as the plot of the game! Of course, at the end it once again turns out to be just Dr. Wily again, and i can't for the life of me remember how they make this make sense-- I never beat this game, and i'm not totally certain i even beat Protoman.
By the way, if you happen to have a copy of mega man 3 sitting around, try going back and pausing the instant that protoman's flute starts playing. It turns out that the song he's playing is about four times as long as the clip you hear, and if you pause while it's playing you get to hear the whole thing.