Dog Run III - Snake Skins

Dog Run is a three-part challenge in the Fallout: New Vegas add-on Old World Blues.

Challenge requirements
The Courier must:
 * 1) Complete the X-8 Basic Testing Program in the X-8 research center.
 * 2) Complete the X-8 Advanced Testing Program.
 * 3) Complete the X-8 Testing Program...with Nightstalkers!

Effects

 * Grants 100 XP upon completion of a challenge part.
 * Unlocks the perk DNAgent.

Behind the scenes
Dog Run II: Who let the... could be a reference to Baha Men's song "Who Let the Dogs Out".