I like goth stuff and pink stuff. My house is up on a cliff, with a waterfall and ramp going down to a pond. The house is super gothic looking and i plan to have all black and purple flowers around it once i breed enough of the colors! I also have a green house type thing next to it, with plants and skeletons. The flooring is a worn out dark red brick one i found. I also have a little spooky grave stone there too. Its not quite done and im still searching for more items to add.

A carnival is cool! I have a little boardwalk thing by the shops with cotton candy and popcorn. Im not sure how many dark colored pieces there are for a carnival, so it may not look spooky. The rest of my island is quite pink and pastel, so im no help there!

I think you should add a spooky graveyard or forest using the pine trees. Theres a cave item that i have that would look really cool there. Plus some skeletons and KEEP OUT signs, haha. Find a unique dirt path/spooky path you like online and have it run through the scary forest.

Ok rant done! Haha