u/Agreeable-Annual3672

Y'all I'm tryna find this horror book that I read as a kid but none of the search results are bringing me the right book. It's like about these two kids who are beset upon by a bunch of monsters because their uncle is a monster hunter or something. It's filled with a bunch of pictures of creepy monsters that are superimposed onto real photos and then at the end the uncle turns into a Jack Russell Terrier. The uncle also looks like a Tim Burton's Houdini and in the photos he's portrayed by someone in live-action. Please help me!