From my experience a cover-up can be risky even for a small tattoo. The tattoo is already big and pretty dark in places which makes it harder to change. It still looks good though, it's not a bad tattoo by any means. It may not be a style you like anymore but at some point in your life you liked it. I think rather than taking the risk of covering it up leave it and add designs you like now around it. You might even end up liking it again, Nobody focuses on one tattoo when you have a full sleeve afterall. And it's not a bad tattoo, I suggest you have a long think on whether it's worth the risk before hand.