We all know what worms are and that they are one of the most successful groups of invertebrates. It wasn't much of a surprise when they were discovered to exist in the world of Spec.
This group of worms contains many species of aquatic invertebrates, most notably the infamous bobbit worm of the Pacific Ocean. While this creature is absent from the world of spec, another creature, just as terrifying, fulfills a similar niche.
Gummer (Arcticovermes gummerphobis)
A jawed worm which builds sack casings around themselves -- yes, themselves, since every specimen discovered thus far has been reproductively locked with others of the same species, as well as having sticky threads between themselves and the noxious casing. The casing is the "Spec Graboid"'s first line of defense, with the heads and bodies retracting into the shelter of the casing, leaving a predator with only toxic "cotton candy" to bite at. When prey approaches, a head of the creature darts out and bites into the fish or crustacean.