Earlier this month, GM Authority said one of its insiders explained why Chevrolet wouldn't develop a Silverado to directly rival the Ford F-150 Raptor and Ram TRX. Declining to build a haul-ass off-road Silvy doesn't mean that Chevrolet won't do more with the stock Silverado ZR2, though. We've seen a camouflaged version of the upgraded Silverado ZR2 Bison developed with American Expedition Vehicles (AEV) in spy photos, and now the two companies have teased what they're about to spring. A short teaser clip reveals a few highlights of what makes a ZR2 a Bison, starting with a new bumper. The stock ZR2 bumper is a special unit shaped to provide a 31.8-degree angle of approach, its corners cut to provide plenty of body and wheel clearance on the trail. The front bumper in the teaser restores fog lights at the edges, and makes a place for the front license plate, which the regular unit does not. The corner fogs are standard practice on AEV aftermarket bumpers, usually fitted to trucks with substantial lifts.