I like how although exaggerated, they reflect the styles of the 40k races perfectly. This guy and the Wrack are quite similar in theme, but you make them clearly very different.
If strogg from quake would have appeared on 40k earth, they would be like "Hey captain, you brought us to stroggos again! Are we out of fuel or smth? But they speak strange language and i cant establish a link to command. Whatever... Lets find us some habitat planets to harvest genetic material from and bring here."
Bow down before Grandfather Nurgle!