The Lilliputians are Fables who live at the Farm. They first appear in Fables #14 — "The Mouse Police Never Sleep: Storybook Love Part One."
History
Lilliputians hail from the small city of Lilliput, located on a remote island in the Homelands, having never ventured out beyond their borders.[1]
Finally, word of the Adversary's conquest of kingdoms reached their small ears, and they decided to help in the resistance effort. When a small ship full of their soldiers reached the beaches of a foreign land, they noticed quickly how everything was bigger than they were, animals and people. They called these giants "Gullivers," after another giant male their people once came across. Unfortunately, the Lilliputian Knights were stranded once their ship was destroyed by a large goblin, and they couldn't return home.[1]
They heard some of the locals whispering about a portal to a new world where the Adversary's forces couldn't reach, so the knights embarked on a new journey across the land of the Gullivers to the portal where they can build themselves a new home, since they have no way of returning to Lilliput. Because of their diminutive size, they had to live on the Farm, where they built a town called, fittingly, Smalltown.[1]
Physiology
Lilliputians look much like regular humans, except that they're only six inches high.[1]
Original source
The Lilliputians are based on the characters of the same name from the novel Gulliver's Travels.