Edit2: found an alternate link for that pic
here is a picture of a Wolf Eel

and heres a few pictures of Sea Spiders.

It may be hard to tell what this is at first glance as it's all bunched up, but it is a sea spider, and its feeding on a sea anemone.

here is a Deep sea, sea spider.

I don't know what species the devs got inspired by, probably one of the bulkier looking species.