who is this?

[Dagger]

I think that's spy troops duke DUKE (v14), YOJOE.COM | YoJoe.com: Dedicated to the G.I.Joe of the 80's, 90's and beyond!

[Net-Viper X]

Found it, Helmet is from Duke version 12. Its part of a Spy Troops disguise.

[zartan74]

AH...mystery solved...

[Net-Viper X]

And for the sake of completeness, the shield is from Grunt version 6. Apparently its part of a Cobra Claws disguise, even though Claws never had a shield...

Would look cool for a custom Alley-Viper Commander though!

[Storehouse]

Specifically, the Spy Troops Duke that came in a two-pack with the first Pit-Viper.

The figure in the photo itself is from a Valor Vs. Venom Wal-Mart two-pack with an arctic/urban camo Neo-Viper. The other packs were:
-Gung-Ho (tan repaint of the first Joe Vs. Cobra figure) vs. Iron Grenadier
-Roadblock (tan repaint of the Spy Troops figure) vs Cobra CLAWS