Leyendecker

Leyendecker was a famous artist and writer who lived in Equestria. He wrote a book that Spike would study while preparing for Rarity's birthday.

Behind the scenes
Leyendecker appeared on "Cover A" of, the 28th issue of the Friendship is Magic comicbook series by IDW Publishing. He is most likely named after the real-life artist, J.C. Leyendecker.