I've been running the Royal Jelly Palace a lot lately, and all the royal minis seem to do is wiggle about without performing any sort of animation where we see them from a different angle.
On a similar note, it took me a long time to realize that the gold key is a 2D sprite.
Yes, the mini's and keys pull a common Nintendo 64 trick of using a 2d sprite.
It blew my mind too but now I got myself thinking why I didn't notice it sooner.
The sprite itself just sort of expands and contracts. Either that or I haven't been paying close enough attention.
Not noticing the key was just sort of my brain being derpy, but I never would have thought that an enemy itself would be 2D.
The cake minis are also 2D sprites, as are certain devilite projectiles among various things. I'm also pretty sure there's at least one or two weapons with a 2D particle attached or something like that, such as that ribbon on gunslinger hats.
Oh yeah, not to mention certain items that only have one face and are completely invisible if you look from behind it. Such as certain walls, glows among other things.
Did you know if you could adjust your camera angle, those minis would look skewed?
Did you know that despite the fact that you cannot rotate the camera, Grim Totems will always rotate along the X axis to face it?
"Are the Royal Minis 2D sprites?"
Well, technically yes, but they seem to have different sprites during their attack animation.