Elder Things

Elder Things stand about eight feet tall, with a six-foot torso, and have wings which neatly fold up into their bodies. They communicate by piping whistles and can sense without light. Elder things came to Earth a billion years ago and may have accidentally started terrestrial life through experimentation. They created the Shoggoths to serve as slaves.

In the RPG...

Elder Things have 7-point armour, so bullets will barely hurt them, and they get 5 attacks per round with an average of 10 damage each time. If seized by them, the opposed STR roll needed to escape only has an 8% chance for an average Investigator. So Elder Things are quite deadly. 

    The Elder Things' CON and INT have been increased in the 7e Malleus Monstrorum. They averaged 110 CON before, which is only just above human range, but are now 190, and their INT was within the upper end of human-range before, whereas it can now potentially get up to 120. Both of these changes make sense seeing as they should be hardier and smarter than humans.

In a video game...

Elder Things would be great in a video game, though due to them existing millions of years ago, there would need to be either time-travel involved, or cryogenically frozen specimens like in At the Mountains of Madness.

In a film...

Not everyone knows this, but Elder Things have actually appeared already in a film—Hellboy 2. Seen once being strapped to a surgical table, and again walking past in the Troll Market. Sadly they were only fleeting glimpses, and I'd still love an At the Mountains of Madness film.