I appreciate the feedback! The polite suggestion is welcome, but the game is not going to include muscle expansion, because the scope of art is locked down as much as anything. (also, I can’t legally include a Mindflayer, as they are copyright protected by DnD XD)
I wonder how easy a defense would be if you just took a mindflayer and called it something different - can't exactly copyright the idea of a human with a squid for a head. Otherwise most depictions of Cthulhu would be in a heap of trouble.
I know they exist in a couple Final Fantasy games under the term "soulflayer," but I don't know if that's something they did with permission from Wizards of the Coast or not. (Though I imagine Square Enix wouldn't want to get in hot water with WotC again after what happened with the Beholder in the first FF game...)