Fate of All Fools is an Exotic Scout Rifle with high Impact. It features the best Range among peers (94), but also has the worst Stability (24). This lack of Stability is mitigated by Zen Moment which increases your Stability when dealing damage.
Originally, FoAF had a 7-shot magazine (increased to 13).
World's First Fate of All Fools
On November 5th, 2014, Bkbunny87 posted a story on reddit about her husband, tRiFecTa01, playing Destiny as part of his physical therapy. After reading this story, Bungie gave her husband the world's first Fate of All Fools. Prior to House of Wovles, it was the only one in Destiny.
On March 6th, 2015, it was spotted in-use in the Crucible (with a new screenshot taken).