Frozen crabs for human consumption have been cooked(steamed, same with crab meat and legs). That being said, I am not at all sure what cooking does to the meat that makes it undesirable as a food source. The "common" wisdom is to feed raw but, other than that is what is in the ocean, I have never found an article that explains why it is not appropriate to use for feeding cephs (or fish in general). Not having found an article, however, does not mean that there is not a good case for raw.
I live right on the ocean so I catch the crabs myself. They are asian shore crabs (invasive), so I figure I get free octopus food and help out the native ecosystem a little . I freeze them for a couple weeks prior to feeding because I don't want to have to deal with any parasites. Here is the video of the day old octos.
I will def post pictures of Victor! Relatedly, I'm planning to head out to H-mart next week as they are getting a fresh shipment in. I will be sure to keep you guys updated when I bring one home.
Heres the video of the day old O. Bocki (probably). It's not super high quality because my camera had no interest in focusing on them (they were sooo small)