When most people begin searching for dragon tattoo sketches, they think of the logical first step as typing it into Google or Yahoo and seeing what turns up. The problem is that search engines such as Google and Yahoo can't look at dragon tattoo sketches and decide what is cool, original and innovative. They have to rely on the text on the page, links coming into the site and the age of the web page. All of these factors mean that search engines more often than not will throw up a site that has good information about the tattoo design that you are looking for, but the actual gallery will probably be be rubbish.
Also, the pages that show up on the first page, which are the ones that you are likely to look at, have been seen by millions of other people. So even if you are lucky enough to find a decent tattoo through the search engines you will be inking yourself with the same thing as everyone else. This isn't what tattoos are about! They should be original, and express your personality and feelings.