Words in English that end in “-us” and pluralize to “-i” are from Latin, such as cactus/cacti or focus/foci. However, “octopus” is from Greek, and its correct pluralization from Greek would be “octopodes.” In English, we have also adopted “octopuses,” which fits our standard pluralization rules.

So, “octopi” is actually a language mix up, though one that’s so common that it seems to be accepted in English.

Octoplenty

Actually, octopi is the “erroneous” one. Although it is a very common mistake so might make the shift to recognised before too much longer.

Everyone still understands it, so it doesn’t matter.

Now I wonder how Octopie tastes like. It’s probably related to seafood pizza. 🫠