alright, we all know the ork klans right? i thought so, if you dont heres da list
http://uk.games-workshop.com/orks/ (at the very bottom) so heres how this is going to work. You are going to make your own klan make Core, Common, Rare mobs, Clan Bosses, and Clan Warboss upgrade. Write fluff if you wish! This can be a variant on a list (Death skulls with Burna Boyz as Common) or an entirely new one. No making Dreadys, Killa Kans, Battlewagons, Looted vehicles, Wartraks as troops!
Example : 'Da Metal Teef Klan
Core Mobs: 'Ard boyz
Common Units: Tankbustas
Rare mobs: Kommandos, Stormboyz, Skarboyz, Flash Gitz
Clan Warboss Upgrade :Warboss recives Iron gob for free; if Warboss has a Bodyguard recives 'Eavy Armor for free.
Clan boss upgrade: 'Ard boyz mobs that number 20 models recive Iron gob for Free
Go for it!