Some people like the idea of having a scary looking clown tattooed in their bodies and other simply don't go for what they consider is too much to handle. Evil clown tattoos are fun to watch and the fun part is also having people stare at it for a while. Lots of people used to be scared of clown when they were a child and looking at a scary clown bring back those memories when a real clown would approach them with a balloon and cause a mixture of screams and tears.
People live fascinated by clowns most of their lives since it is a character that has been there since they were toddlers. Having a clown tattoo depends on the meaning it has for that person who wears it, in other words every individual got their own personal reason to go for one of those.
Who can forget that movie called It? It was thrilling and massively scary to see a clown pop up in the sewer and try to persuade us to approach him for whatever reason, scary indeed.
Being able to create an awesome piece of work when creating a scary clown is very important, a scary clown tattoo is not the same as sloppy looking clown. Make sure you find the right artist for this kind of work, as I mentioned before: Try finding the best artist and pay for quality, it will be more expensive to have to go somewhere else to get it fix and you will have to endure the healing process by showing a tattoo that looks like crap.
If you decide going for a scary/evil clown tattoo try making sure to get a custom made work instead of choosing something everybody has unless is what you prefer to have.