This duplicitous Skaven is just going along with what its superiors want, disguising its abilities with a masquerade of cowardliness, until the time is right for it to strike! Then it will take its rightful place amongst the elite of the under-empire. Who knows, it may even become a member of the hallowed Council of Thirteen, if not the leader of the under-empire in its vast entirety. When this day comes it will surely lead its minions into a glorious conquest of the surface world. There it will reign at the right hand of the Horned Rat itself as its underlings cavort amongst the ruins of the then enslaved surface dwellers, feasting greedily on their flabby hairless flesh. All hail the Horned Rat!