can I refreeze uncooked octopus that has already been frozen and defrosted?

No....sorry, not a good idea from a food safety prospective.

I always tend to shy away from re-freezing stuff, but I'm guessing that the octopus will handle it fine. We tend to think that freezing is bad, but in the case of octopus, it actually helps to tenderize the flesh, so if you froze it a second time, might be OK. On the other hand, making too much and freezing the leftovers makes a really nice surprise for some later evening when you want a decent meal but don't feel like cooking!

Freezing, thawing, then refreezing is going to negatively impact the quality of the meat. When you freeze meat (or anything that contains water) ice crystals form that puncture the cell membranes. Every time you refreeze new crystals will form and do more damage to the structure of the cells and in essence the meat.

But for most things, you can cook it all, and freeze the leftovers. But not sure about octopus though. Sorry. I'm not much help, am I?

I've always heard you're not supposed to re-freeze defrosted meats and seafood. I'm not sure why though. Hopefully someone can elucidate....