Clan emblem? "Internet cult TK-441" your official motto could be "kill us too many times in a row and get perma banned!"
Or you could have it "a clan for mature gamers over 18" and just FOLLOW the above motto, like 95 percent of current clans.
Seriously though, if youre gonna spend time on a first, make it something cool, like an unlockable orange shoulder patch, or a drivable star destroyer!