title: I'd like to add a sub-header image to a specific tagged page in my Tumblr theme
body: <p>Very simply, like the title says.</p>
  
  <p>I have a single specific tag that I'd like to have it's own header image when viewed.</p>
  
  <p><a href="http://teratoma.tk/tagged/dreams" rel="nofollow">http://teratoma.tk/tagged/dreams</a></p>
  
  <p>I just don't know if anything exists within Tumblr's codex to do it. Can anyone help?</p>