select race boggard
show full equipped list.
has Leather armour, but listed as non-proficient
Bestiary says of Humanoid (and others): "Proficient with whatever type of armour (light, medium, or heavy) it is described as wearing, or by character class. If a humanoid does not have a class and wears armour, it is proficient with that type of armour and all lighter types."
Bugbear (also Humanoid 3) is proficient with Light Armour.
Can't check in version 6.05.04 on, as Racial HD are broken and don't get applied ()
pathfinder core supplements rule set