Catching Elephant is a theme for Tumblr.
Please look through all the answers here before asking a question. The same questions keep coming up. A lot of customisation can be done with custom css. Try googling css background for example.Catching Elephant is a theme by Andy Taylor
You can change the font with custom css. For example:
body {font-family:georgia,serif;}
or
body {font-family:verdana,sans-serif;}
To hide the tags. The simple answer is to just not tag your posts. The harder answer is to go into custom html and remove the tags line of code from each post type.