Grenadier Models had one mind flayer sculpt back when they had the AD&D liscense and it is not great. It always looked like it was trying to do the robot or the safety dance.
This might have been the first mind flayer miniature ever made; it is certainly the first and only mind flayer model I ever owned. When I went to paint mine, I had to look up ‘mauve’ (the color of mind flayers per the Monster Manual) and eventually decided to paint it in a mix of purple and silver, with a red robe. That paint job did not hold up well (it was one of my experiments with Testors enamels but for some reason the paint did not adhere well — maybe I didn’t wash or prime the figure?
Anyway when I was given a second mind flayer (again a Grenadier), I decided to repaint my first one too and do something about the pose. In the end they sat in a box for months before I used a mind flayer in my D&D campaign and I realized I still hadn’t painted either. I did not manage to finish painting them before the mind flayer menace was dealt with, but better late than never.
The one on left had his hand opened up to receive a sword. There was a mind flayer with a flaming sword in the campaign, Bobdobolina, that this figure would have represented. The one in the middle just had his left arm rotated. I think they look alright. The white skin on the first looks good to me. Maybe mind flayers should have color-changing abilities like octopodes anyway, given their heads.
On the far right is a Minifigs iron maiden. Actually, it’s a recast of the Minifig design by GFI. I am not sure if GFI is still casting Minifig sculpts. My iron maiden had some defects (cracks and some details not filled completely) that suggest a lack of quality control. Maybe the caster was in a hurry — a few other figures I bought around the same time from that line have problems too, but since I got them from a third party (Noble Knight) I didn’t bother trying to get replacements. In the case of the iron maiden, the cracks and such actually don’t bother me anyway; it just makes the maiden look well-used.