non-conformist

Somebody who hates baby kittens, thinks the earth is flat, thinks vaccines cause autism, posits that climate change isn't real, that the moon landing was just a hoax, and every other nutty conspiracy theory you can think of. Many people would think non-conformists are simply people who like unpopular stuff. But realistically the "unpopular" stuff is still rather popular to a certain degree (e.g. classical music). The REAL non-conformists are those that actually like or support something that literally nobody would like or support. And those people are typically conspiracy nutjobs or psychopaths.