Doesn't it actually come into English from Latin (in its later academic/international use, rather than the classical language)?
But in any case, it's English, not Latin or misspelled Greek, and octopi seems to at least be the oldest evident English plural of octopus, AFAIK, though octopuses seems to be experiencing current popularity, and octopodes is just...no, though the suggestion once made that English ought to adopt octopods, wasn't bad, but never caught on.
But in any case, it's English, not Latin or misspelled Greek, and octopi seems to at least be the oldest evident English plural of octopus, AFAIK, though octopuses seems to be experiencing current popularity, and octopodes is just...no, though the suggestion once made that English ought to adopt octopods, wasn't bad, but never caught on.