your Idea is great, only suggestion, the 1st Head, add more Shade effect and a bit Metalic Effect to make it more Realistic will be Very Good.
the 2nd one is Perfect, keep up your Great job Chicken :3
I did work a bit more on the robot from portal head but i dont have ideas for the back of the lion head... FUUUUUUUUUUUUUUUUUUUUUUUUU.... any suggestion?