Am I missing something about Skinwalker?

[Desiani]

A few guides I've read for class handbooks mention Skinwalker as a Featured race. For the life of me I can't find this race in my Advanced Race Guide pdf.

Is it an erata that I have missed or posibly my PDF is out of date? @.@

Where is this race mentioned in Paizo Material?

[Dusk Eclipse]

According to the PFSRD (http://www.d20pfsrd.com/races/other-races/more-races/standard-races-1-10-rp/skinwalkers-10-rp)they were introduced in the Pathfinder Player Companion: Blood of the Moon

[Ssalarn]

The race appears in the "Blood of the Moon" player companion. It's a race reminiscent of the shifters from 3.5's Eberron setting.