Akim to I Am Error GBD is another example of a background character that called more attention that is should.

The "Green Biker Dude" (also known as GBD), as called by fans of the series, was a unnamed green Maverick Hunter who came along with X on the intro stage of Mega Man X2. As his name suggests, he is green, he rides a Ride Chaser bike and he is a dude. He was destroyed by the shots of a Cannon Driver during the beginning of the opening stage of Mega Man X2 while popping a wheelie. In the whole series nobody talked about him before, and nobody talked about him since.

There are many theories about why he became so famous among fans since his apeearance lasts only a few seconds:

Maybe because he was always remembered by his acts of bravery, the reploid who runs the role of a common soldier and cannon fodder that rushes to the enemy, to fight for a better world, he did his best, no matter the circumstances, and then he died fighting for what he believed in.

Or maybe because he was just useless.

In the Rockman X2 manga, there is a similar character called "Boy" that was killed in the first chapter.