YMMV on exactly the grade of Nightmare Retardant. They are described as six feet tall and eyeless, shambling about and squawking loudly, a far cry from this◊. A bit unsettling depending on the reader.
So, this◊ is an albino penguin. If it was 6 feet tall and eyeless... yup. Still cute.
Unless you interpret them as looking like this or this. Ew.
Values Dissonance: The reader is meant to sympathize with the "upper-class" Elder Things over the "lower-class" Shoggoths, which were manufactured en masse by the Elder Things to act as their servitors. Admittedly, it's easy to do when one is rational and ill-fated and the other is a formless, possibly non-sentient mass of black goo trying to rip your head off (literally), but still. It's like a biological ancestor to the Robot War.
Except the Shoggoths were never supposed to be sentient, they just sort of mutated and ended up with it. Imagine tomorrow if our construction machinery became sentient and decided to try and kill us because they were sick of working for us. They weren't slaves, they were tools that randomly grew a brain and decided they didn't want to be tools, not to mention there's no real insight into exactly what kind of sentience the Shoggoths had.