Jerboa

Don't know about Jerboa, but Connect for Lemmy has a feature that you can type in keywords you want to use as filters, and posts with those words in the title are automatically hidden.

I use it to filter out political posts, and after using it in this way my Lemmy experience has drastically improved. You may be able to use it in a similar way for spider related stuff, maybe Jerboa can add a similar feature.

As far as images without anything to note its a spider in the title, you'd need to add image recognition, which is something more likely to be added to Lemmys backend than as a clientside thing.

Having an option that treats all posts like nsfw -- click to view image -- would work, right? That sounds like something I wouldn't mind having on by default as well.

To fair, I think the only way to executevthat would be to implement an image recognition algorithm, as I don't see lemmings marking arachnids as a tag on their posts even as arachnophobia is one of the most common phobias out there (to be fair, I think Mastodon has stronger culture for tagging trigger warnings).

That said, if you have SLIGHT arachnophobia, I'd almost recommed exposure thereaphy with a professional psychiatrist, as if you have some tolerance, it's easier to work on than full on panic without ant tolerance.