Octolings
Octarian Fighters, considered to be the Octopus equivalent of Inklings.
They are capable of switching form between Octopus and Humanoid, as far as we know, only female Octolings can switch between Octopus and humanoid form, there's been no news if Male Octolings exist.
Octolings are equipped with Ink guns, and bombs.
As with them being the equivalent of Inklings, it is most likely that they behave similarly, so treating them as any other inkling should be effective.
Easy Pickings
Octolings seem to have generally low HP, and they aren't too precise with their shots, but don't let that lower your guard, as they can take you down when you least expect it, they seem to work better in pairs.
- Octolings actually can't see you when your under the ink, use that to your advantage for a sneak attack!
They also seem to throw a splatterbomb whenever they see you, so be on the look out for it, and make sure you don't get hit. a few good shots will finish them with ease.