From the website:
This set contains 10 head swaps designed to fit 28mm "heroic" miniatures.
Designed by Tom Vlatko aka "MajorTom11". Sculpted by Bob Olley. Painted by Aleksander Kidawa.
"Blasphemous experiments led to a crossbreed between human and alien. Devoid of human emotions and with an alien speed and savagery they were brough as a perfect soldiers. At it least their creators thought so - those cunning abominations can hardly be controlled."