This is a Warhammer 40 000: Drukhari Haemonculus [Direct Range]

This 11-piece plastic kit makes one Haemonculus equipped with an array of deadly surgical instruments and a splinter pistol. His body is born aloft by a grotesquely elongated spine, as he drifts across the field of battle with a macabre elegance, gifting a slow and painful death to all those who cross its path.  

Note this kit may come supplied in plain packaging from the supplier