Kieran Murray is an aspiring Australian filmmaker now living in Los Angeles. When he travels, he takes pictures and leaves room for his toy Godzilla figurine named Ryan Godzilling. Then he Photoshops the monster into the images later. The monster appears in different sizes, depending on whether he's helping Murray with the laundry or getting ready to wreck city buildings. Or just enjoying the scenery.
Notice the details, like Ryan's shadow and reflection, and the people who are watching in some of the photos. You can see the "best of" collection at Behance. One image (Las Vegas) may be NSFW. See all of Ryan Godzilling's photos, categorized by location, at Instagram.