Scretch owls. I got under one that was in the tree I was under hunting for deer. It was completely dark and I was freaked out a little to begin with. As the Doc said in the movie ( The Thing ) ' I hear things. I hear strange things out here ' . That makes me a little uneasy to begin with. I was trying to relax waiting for the sun to rise. All of a sudden one of those owls went off and I sh**, pissed, puked and belched with a finishing 4 minute fart after that. I vowed the next time I get under a tree in full darkness I will have a set of ear plugs in. Blood curdling scream is all you hear and when you are 20 feet below it, it's a hair raising experience to say the least.
My father who I never knew to be afraid of anything said a screech owl scared the holy crap out of him one night while on a coon hunt. Bobcat jumped out in front of him at the exact time the owl let loose right over his head.