While there are actual Ottoia creatures out there, for a long time they became the nightmare creature to think about. Why? Due to how they were utilized in books or movies. Ottoias are relatively small but what if they became gigantic?!? In the movie Deep Rising, an Ottoia creature named Argonautica showed up and scared a lot of 90s kids in 1998.
The concept of the character in the film is that it is simply an evolved version of the Cambrian Worm, which we know as the actual Ottoia. Yet if you see the movie, what they do with the character makes it one of the most horrifying sea creatures imaginable. They give it the traits of an actual giant Cambrian Worm while also making it come off as similar to the Kraken. Oh my!