Someone who excels at life. In the context of videogames, Peacho Killa can be used a as by-word for "Pro"
However, Peacho Killa is a name that can describe anyone who has excellent skills in any activity. Peacho Killas metaphorically kill Peachos in their spare time.
J- "I saw some Peachos walking down the street the other day, know what I did? I blew their fucking brains out with my glock! Got brains all over my nice shirt too."