Teebu's Blazing Longsword

Teebu's Blazing Longsword is a one-handed sword with a fire damage proc.

Source
This weapon is an extremely rare world drop from level 61 and 62 elite mobs. There is also the possibility of looting it from a Big Crate of Salvage.

Trivia

 * This sword is displayed on the inner cover of World of Warcraft retail box worn by a level 60 dwarf warrior named "Hammerfall".
 * It is a tribute to the iconic Jedi swords, lightsabers. It can also be transmogrified!