Avatar: The Last Airbender is an American animated television series that aired on Nickelodeon from 2005 to 2008. It is set in a world where some people have the ability to bend the elements of water, earth, fire, and air, and follows the journey of the Avatar, a young boy named Aang, as he tries to defeat the evil Fire Nation and restore balance to the world.
The font used for the "Avatar" part of the logo was custom built although replicated by FontGet's Avatar Airbender Font which is licensed as free to use. The font used for the "The Last Airbender" part looks very similar to Herculanum Roman Font which is available to purchase here.