You may date yourself if you remember the robot from the original Lost in Space. I downloaded 2 side views from the web and placed them with the Raster Image command. Then it’s a matter of Revolves and Extrusions. Command J was used to make the bubble semitransparent. The arms were made with Pattern Geometry along a Bridge Curve. The legs were made with parallel Planes and Intersection Curves which were then Tubed. The bottom tracks were made with Pattern Along a shaped line. The buttons on the front panel were projected onto the surface and Divide Face was then Thickened.
The inset in the main body was the trickiest part. I Shelled the trunk then used Extract Geometry on the inner face. Trim Body made the opening in the shell.DOWNLOAD PRT