See the rule below vis a vis non-alphabetic double acts. As extra ammunition note that Shanks is short for Shanks Pony. Pony, in Cockney Rhyming Slang is short for Pony and Trap – which rhymes with Crap.
Bigfoot on the other hand is a mythical beast occasionally sighted in the Rockies, and more often sighted in re-runs of Bigfoot and The Hendersons. Despite John Lithgow being in B&TH (or perhaps because) it was crap.
Some say Sweet Like Chocolate was a perfect proponent of Bubblegum Garage. Fine, but have you ever eaten garage flavoured bubblegum? It tastes shit (like crap).