Kevin Smith unveiled the trailer for his upcoming horror anthology film Killroy Was Here over the weekend as part of Comic-Con at Home, and I'm warning you now, it's pretty gory. The film was inspired by the "Kilroy Was Here" graffiti depicting a bald man with a large nose peeking over a wall. Smith has now given the character a backstory, as Kilroy is depicted as a Vietnam veteran who uses the deadly skills he learned as a special ops soldier to become a Florida swamp monster of sorts -- one who protects children instead of preying on …