You know how the Dark Elder are supposed to be lightly armoured fast moving and sleek looking and then the Incubi come along looking all hefty with their 3+ armour saves or how the majority of the Imperial Guard forces are mostly human based and the Orgryn's trapse into the army list and stick out like a saw thumb and lets nopt even mention ...... (vespid)......
I was just wondering if you guys could think of any other units that stand out like the black sheep of their respective army lists? Did you have any favorite distant cousins who no one likes to talk about at the family gatherings.