Premise - Character Thumbnails

I have done a few more rough thumbnails for my alien character. The top image shows thumbnails for the 'younger' alien, so I have tried to keep his features present while making him look smaller and cuter. His head here is large in proportion to his body, but I feel this might work for the child version of him, and then I could have his head more humanly proportioned when he is older. 

The image below shows thumbnails I did for the alien when he's older, but the one in the middle and one on the right show him with the 'attack mode' idea considered. In his regular version in the middle, he has small bumps over his head and on the sides, which could also represent ears and be a good way to help show expression throughout. While their existence could seem irrelevant the whole time, by the end he could transform into something similar but scary, like the one on the right. For example, horns could force their way out of his skull through the ear bumps, and the bumped slits on his head could open, revealing multiple eyes popping out all over his skull. His jaw is fairly large so could break/drop and widen, and he could increase in scale, as well as his hands and fingers becoming more devilish. While I've still not decided if this is the route I'll take, I do think the features that transform could have a strong impact.