The gilacorn is a small, lizard creature that scavenges the desert, looking for food. Many years in the past, giant gilacorns were alive and posed a threat to a tribe living in the area at that time, the beetle-headed merchants. However, only the diminutive version of this creature was alive in 100 ASC.
According to old legends, the subterranean ancestors of the beetle-headed merchants, the first humans living in the Si Wong Deserts, were constantly attacked by giant gilacorns, until they mimicked the appearance of sour beetles, the only creatures on the desert floor not palatable to gilacorns. However, these giant gilacorns were extinct by 100 ASC.
In the Si Wong Desert, one gilacorn stole an egg that Appa attempted to eat. After finding an egg in a nest, Appa was ambushed by the creature, who snatched the egg and quickly retreated, holding the egg over its head.
Long ago, gilacorns were equipped with a whimsical but deadly unicorn horn. In more modern times, it walks on its back legs like a basilisk lizard or a mongoose dragon as it walks on the surface of water.