Okay, that's pretty cool. Well done.
But, there are some things I don't like about it, and as always I'm going to freely, and bluntly, speak my mind on why.
It might just be me, but his eyes look like boobs. It's creepy.
(They're also desaturated and don't use any of the deep orange color you see on the cheek)
His mouth tendril things looks like sausages. In the show they're extremely expressive, and don't just hang there like... dead meat.
(They also don't use any of the nice orange)
The tendrils also don't really look like they're casting any sort of shadow. it's a little darker under them, but that's about it.
The tendril in the back looks much shorter than it should be.
The tongue looks too bright to be inside of his mouth cavity, while it looks like from the shapes that it is inside of his mouth.
There the shirt meets his chest it starts getting blurry and darker. With the light source above his head, you wouldn't and shouldn't see and shadow from the shirt. That area should be as dark as any other.
The shirt also has that weird blurry shading as it approaches the jacket.
The jacket doesn't have enough wrinkles in my opinion.
The blood on his jacket looks really weird, as it has been applied symmetrically on his body.
He does NOT look expressive. From the blood I can assume he just messed up an operation, and he should be shocked.
He therefore hasn't remained true to his character, who is extremely expressive.
How you'd express that is have his claws up in the air. (Maybe have his tendrils waving around like they do in the show.)
Like this.But he currently isn't doing any of that, so he looks really passive, other than yelling.
I understand it's a WIP and you may have already know about some of those problems, I was just stating my observations.