Toy design - head, next attempt
Here we see another approach. There's only one moving part on the head, and it's a tiny flip-down (flip-up?) visor. Here, it goes from cat head to transformed cat head to robot head. Literally the only difference between the second and third images is orientation.
The resulting robot head is very impersonal and helmet-like, with the mouth area covered by a thick slab which could be anything from a beard to a vocal restrainer. I originally imagined the character to not be much of a talker, so this fits. The kitty-ears problem has become less so (they could now be cheekplates for a helm, for example). As with the previous design, all articulation in one neck would also work in the other neck.
He has no nose here, adding to the alien robot look. I could give him one, which would swing back into the depths of the cat head when the visor flipped down, so it's not an absolute requirement of the transformation.
He looks less like a sad robot with kitty ears and more like a bald, bearded biker, I think. In addition, the head reminds me a little of Krunk, Snapdragon's head. Especially the shape around the top of the head. The beard, not so much.