In line with the shadow arts of Pilobolus, I also came across the works by the couple, Tim Noble and Sue Webster. Look Deeper, or rather, Darker.
Falling Apart. 2001. Mixed Media.
Real Life is Rubbish. 2002. Mixed Media.
Kiss of Death. 2003. Taxidermic animals (Carrion crows, Jackdaws, Rooks, Minks, and Brown Rats), Various Bones.
A Pair of Dirty Fucking Rats. 2005. Mixed Media.
Dirty White Trash(with Gulls). 1998. Garbage, Seagulls.
HE/SHE. 2003. Wielded Metal. 
HE (Dayview). 2003. Wielded Metal. 
Sunset Over Manhattan. 2003. Cigarette Packets, Tin Cans, Wooden Bench, Air Gun Pellets.
The Crack. 2004. Wielded Scrap Metal.
And if you all don't get the last work, there is a reason why it is called the crack. Treat the shadow as positive space instead and you might see the hidden portraits =P