Update: My octopus arrived today. He indeed was an O.briareus. Unfortunately, he did ink in the bag, but alive. So I got him in my aquarium a lot quicker than I would have liked. He first went upside down, then after a minute or two, he flipped himself over and went into a ball, and instantly put on a show of changing colors. I will post a pic of him later. Crossing my fingers that he will be okay.