Strange links at bottom of home page

I’ve recently noticed a series of strange links, mostly casinos and card games and such, at the bottom of my site’s homepage, where SEO tags are sometimes seen. These links are empty, when clicking on it I get a 404 error. I didn’t put these words there, I don’t know what they are or how to get rid of them! Can anyone help, please?
http://imagineartanddesign.co.za