This is a Wizkids Brain Eater rookie. To bring your rookie with head and base removed, the head is replaced with a GW zombie head.
Wizkids Horrorclix Insect Man (Rookie) with GW zombie arms and head. The guy could fit in as a prisoner from the Umbrella Corp.
Wizkids Horrorclix Frothweiler (rookie) -- I call him my "Rotted-weiler". I cut off the annoying boney spikes and tail and trimmed the ears. Again, this could be a lab dog or security dog for the Umbrella Corp. I know this was not the greatest zombie flick ever, but it had great zombie content from in miniatures/customization standpoint.
The CMG rookie clix stuff is great for making zombies with, and it's cheap! The Horrorclix listed above go from $0.14 - $1.09 on Ebay each. Prices are usually like that for the others, except for the Corp Response guys and their Zombies that go in the $2.26 - $9.99 range (cheapest)! Really wish they were more common, as they are really nice looking in the pics.