That is said dog. His hea'ds not unside down there, cos the mask wouldn't fit, but don't worry, when Oldman gives the dog what-for , he's all crazy twisted head.
An old man confines to a wheelchair. He gets out, and my mate jokingly said he'd do a spider-crawl like in Excorcist. He does, and his head twists round too, a bit like the dog. That poster is a lie. He does not walk on walls.
Also, he's not nearly as awesome as his poster makes him out to be
And lastly this isn't really what it seems. In fact, I don't know what the promotional people were thinking when they came up with this poster.