Is octopi plural for octopus

The Word "octopus's" is a singular possessive noun, a Word for one octopus that shows something in the sentence belongs to that octopus.

Example: The octopus's color changed to blend into its background.

There are two accepted forms for the plural of octopus:

• octopi (possessive form octopi's)
• octopuses (possessive form octopuses')

Examples:

• The octopi's tank contained four octopi.
• The octopuses' tank contained four octopuses.