https://en.wikipedia.org/wiki/Eunice_aphroditois
Thankfully they don't live on land.
So it was not a dangerous predator, though it could have been poisonous, like many modern millipedes.
> Created by Neal Agarwal
> Illustrations by Julius Csotonyi
> Production by Liz Ryan
> Music & SFX by Aleix Ramon
> Cello performance by Iratxe Ibaibarriaga
Beautiful work.
Fwiw, I've done a pinch-nail-hand-arms 1-10-100-1000 mm "body as size reference" a couple of times around 5ish. And a 1000x "micro view" "pinch is zoomed to arms size" "it's like a scale model or doll playset - everything zoomed together" world of "bacteria sprinkles, red blood cell candies (M&M minis or concave Smarties minis or Sweetarts - there's lots of cell candy analogs), hair poles, salt/sugar boxes". Stories of sitting on a grain of salt and eating... etc; pet eyelash mites. No idea if it actually worked.
I did some user-test videos, now only on archive.org.[1] Hmm... the "Arms, hands" video there now doesn't seem to play inline? - but does wget'ed and browsered. :/
[1] https://web.archive.org/web/20221007220513/www.clarifyscienc...
[1] https://www.scientificamerican.com/article/strange-but-true-...
[0] https://www.yout-ube.com/watch?v=pUF5esTscZI
Even if you've never taken a mild psychedelic, this video hits in a similar manner (as sober metaphor).
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I still drive with Neal.fun's Internet Roadtrip (same OP link author), every time I'm out in my workshop.