Corrected entry: When Wallace is backing out of the spare room, leaving Gromit to continue decorating, he accidentally bumps into Feathers. But if you look when Wallace is backing out, Feathers is not there and he was not seen walking up to the room; he just appears.
THGhost
28th May 2012
Correction: Feathers McGraw is a silent, sinister and notorious criminal mastermind of many faces who is capable of disguising himself as a chicken with just a rubber glove. Clearly he is capable of sneaking up on Wallace like that. The fact that he just "appears" was done deliberately.
THGhost