Guids were sizable, fur-laden primates that originated on the Deep Core planet called Tython. These guids possessed a large physique, which was carried by powerful arms in conjunction with smaller rear legs, and they moved by walking on their knuckles. These creatures, whose only natural enemy were the primitive sentients referred to as Flesh Raiders, were the primary species on the mountainous areas of their homeworld, where they fed on the open grasslands. The guid's size and powerful arms rendered them immune to the planet's other predators, such as the manka cat and [horranth], which lacked the intellect to be a threat.
Guids were also present on the frozen planet Ilum in the year 3640 BBY.