You're looking at a latex suit in the shape of a woman! However, it's obviously not a human costume.
It's a two piece with a dark green body, covering everything from the neck to the toes, and a mask with tentacles for hair. All of it is made out of latex. It should be about your size, but why would anyone send you something like this?
You pick the bodysuit up and turn it in your hands, marveling at its shine. It was perfectly smooth, almost like liquid, and whatever it was covered in didn't stick to your hands either. You know that the shine is usually due to some polish, but if that's the case here then you can't seem to get it off.
It's also clearly female with sizeable breasts and hips, long legs and dainty hands and feet.