Star Swirl the Bearded

Star Swirl the Bearded is a legendary unicorn wizard who invented numerous spells during the pre-classical era of Equestrian history. While he never appears in person in the show, he is mentioned and referenced to numerous times, first in the episode Luna Eclipsed, where Twilight Sparkle dresses up as him during Nightmare Night. His visual appearance is disputed, but is shown to wear a dark blue wizard cape and hat, and having a beard.

Personality
Since Star Swirl never has made an appearance in the show, his personality is heavily disputed. Due to his character bearing resemblance to the popular "wise, old wizard" in popular culture, his personality is often influenced by characters such as the wizard Merlin of Arthurian legends and Gandalf of Tolkien's Lord of the Rings.

Star Swirl is often seen as wise and skilled in the field of magic, but lacking in the field of friendship, as suggested by Princess Celestia in Magical Mystery Cure. He is often compared to Twilight Sparkle before she moved to Ponyville and gained friends, a studious and smart, but somewhat anti-social workaholic.

Role in Fan Labor
Star Swirl the Bearded is one of the most discussed characters in the franchise, due to his mysterious past and the praise he recieves for his work in the show. In the episode Hearth's Warming Eve, it is stated that Star Swirl was the mentor of Clover the Clever, one of the founders of Equestria. Princess Luna also instantly recognizes Twilight's costume in Luna Eclipsed, implying that she either had heard of him or personally knew him. He also has a wing in the Canterlot Archives named after him, the place where Twilight locates a time travelling spell in It's About Time. Many fan gives Star Swirl the credit of inventing this spell, and time travel altogether.

While most of Star Swirl's appearances in fan fiction only mentions him, similar to the show, others try to tell the story about him and his life. He is often portrayed in these as an incredible powerful unicorn, many times as Celestia's student or assistant. He often also meets with a grim fate, such as dissappearing in a time vortex, or even transforming into a villian. Discord or King Sombra is sometimes portrayed as the fallen form of Star Swirl. He is also sometimes assosiated with Doctor Whooves, due to the Doctor also working with time.

One of Star Swirls most notable appearances is in the fanfic "A Stitch in Time" by Eakin, where he and Twilight works to repair the balance of time and saving the universe.