Baltimore and Ohio's Challenger type steam locomotive. This was located in Fairport Harbor, Ohio on April That's a beastie right there.
In the 1930s this type of locomotive was seen as a way both to revitalize steam power and challenge the diesel locomotives then being introduced. Description from snipview.com. I searched for this on bing.com/images
Only one 2-8-8-8-4 was ever built, a Mallet-type for the Virginian Railway in 1916. Built by Baldwin Locomotive Works.