Does perceiving an octopus-like form mean it must be an octopus spirit?

Not necessarily. 'Like an octopus' needs to be distinguished from 'actually an octopus spirit.' In religious experiences, something may appear as a dark shape with many tentacles, as though gripping a person, and be described as an octopus. That does not mean it originally was an actual octopus.

When discussing an online account of a fright-cleansing ritual, I did not dismiss the possibility of an animal spirit entirely. Instead, I wanted clarification: was it a complete animal or an octopus-like dark shape? What had the person encountered beforehand, and where had they been? In my understanding of faith, these circumstances need to be considered together. One name alone cannot settle the whole matter.

For that particular article, I leaned toward the second interpretation, negative energy resembling an octopus. But this was only an analysis based on the article. I had not personally helped that internet user or seen their condition. First clarify what is being described and what actually happened, then explore gradually. There is no need to ridicule an unusual name, nor to treat every part of the account as confirmed.