"Hearthbreakers") and three sisters (all voiced by Ingrid Nilson): Limestone Pie, the surly oldest sister; Marble Pie, Pinkie's withdrawn, younger twin and Maud Pie, an older sister who rarely expresses emotion, although obsessed with rocks, is described by Apple Bloom to be "quite nice once you get to know her a little" in "Hearthbreakers". Equestrian characters of unspecified origin (voiced by Chiara Zanni) – A pegasus treasure hunter and the main character of the adventure novel series of the same name parodying Indiana Jones. Author Begin describes her as "essentially a different-colored Rainbow Dash in a hat". In "Daring Don't", the books' author A.K. Yearling (a parody of J.K. Rowling) is discovered to be Daring Do herself, who writes her books as biography disguised as fiction after her real adventures, such as her encounters with the Aztec mythology-inspired villain Ahuizotl (voiced by Brian Drummond) and criminal pony Dr. Caballeron (voiced by Michael Dobson). (voiced by Rebecca Shoichet) – A unicorn baker who lives in a village founded by Starlight. She begins a romantic relationship with Big McIntosh and becomes Mrs. Cake's part-time apprentice in Ponyville before marrying Big Mac in "The Big Mac Question". Non-Equestrian characters by region Tartarus characters Tartarus is a supermax penal colony administered by prison warden Cerberus, a monstrous multi-headed dog. Anyone may enter Tartarus, but no one can leave through its entrance doors:"Lasciate ogne speranza, voi ch'intrate" are inscribed on them. Tartarus provides housing for extraordinarily dangerous creatures; for these reasons, its exact location is classified. (voiced by Mark Acheson) – A powerful centaur who can absorb magic from other creatures, especially ponies. He is based on the character Tirac from the 1984 My Little Pony special, Rescue at Midnight Castle. A thousand years ago, Tirek and his brother Scorpan came to Equestria from a distant land to steal its magic. However, Scorpan grew to appreciate Equestria's ways and even befriended Star Swirl the Bearded. After Tirek refused to abandon their plan, Scorpan alerted Princess Celestia and Princess Luna of his intentions, and returned to his homeland while Tirek was imprisoned in Tartarus for his crimes. He first appears in season four's two-part finale, "Twilight's Kingdom", when he escapes from Tartarus and manipulates Discord to help him steal the magic from every pony in Equestria. Twilight and her friends eventually defeat and reimprison him with "Rainbow Power", powerful magic acquired from the Tree of Harmony.