Planned this one for awhile. Still needs some fine tuning, but its about 95% done.

Made from parts of a Iron Man Hammer drone, a Hulkbuster, and a Alexei head, this custom was finished off with a lot of epoxy.

The main base was the drone. I removed the head and feet, then used a exacto knife to cut off the back plate. I replaced the feet with that of an "Aliens" warrior minimate. The toes were dremmeled off but the rest of the details were kept.

I removed the torso/head of the Hulkbuster and used a exacto to remove the chest piece. I then carefully cut the head from the shoulders, making sure the hinges remained with the head and back.
The HB shoulders and back plate were glued to the HD torso. The head can now flip independently.

Finally, I used epoxy and a dremmel to create the Rhino head and torso. Pop in the Alexei head, add a little paint and there it is!