Does the octopus have an anus? What does it look like?
The anus of Octopus is channeled into its siphon.

Image taken from Carina M. Gsottbauer

Note:


  Siphon is a tube that leads from the mantle to the outside. Octopuses use their siphon to force water out in jets for propulsion and to flush waste products from the anus.


From Encyclopedia of the Aquatic World, Volume 6
By Marshall Cavendish Corporation