About this 3D model

Original headcrab friom the Valve game Half-Life. The original .obj was passed to me by a friend. After some searching I believe the original is this one - http://thefree3dmodels.com/stuff/characters/headcrab_classic/14-1-0-844 I decided it needed to be scaled to fit my cat as he is in desperate need of some extra brainpower and it won't make him any more destructive than he already is. However, as the photos show, cats are immune to headcrabs.