Quote Originally Posted by Sky Shadow View Post
If it were a Latin word, octopus would be a third declension noun, and the plural is octopodes, based on the Greek ὀκτώποδες. It's not a second declension noun.
I sit corrected.

Quote Originally Posted by Sky Shadow View Post
In English, octopuses is the most correct plural. Octopi only exists as a result of mistaken construction, like saying the plural of virus is viri.
Hypercorrected or not, they are all accepted plurals in English. I was personally taught to use "octopi" and "viri" in school.