Jigglers mutated from ordinary squid, and greatly resemble the creatures they developed from. They are rather symmetrical, possessing an ovaloid head, eight arms, and two longer tentacles. Their heads possess two large, lidded eyes, which are extremely sensitive. On the underside of their head, jigglers possess a sharp beak and a mucus sac. The rubbery skin ranges in color from white to rust.
Jigglers have the ability to compress or balloon their bodies. They can grow or shrink their rubbery bodies up to 75%. The average jiggler is roughly sixteen inches in length, ten from its head and six from its appendages. This means that the average jiggler can compress itself into a mere four inches, or can grow up to 28 inches. The creatures able to accomplish this process by contracting their rubbery bodies into an extremely dense mass, or stretching them to their limits. Creatures that are smaller than average can compress themselves to even smaller sizes, while creatures that are larger than average can grow to massive sizes.
Jigglers are solitary creatures. They spend most of their time hiding on the seabed or among rock formations. They rarely encounter others of their species and are sexually hermaphroditic as a result.
Jigglers are hemophages, meaning that they feed on blood. In most cases, this entails sucking their victims dry, but when they feed on larger creatures, they invariably leave them alive. Their preferred victims are sea creatures, specifically sea creatures and mirelurks, but they have been known to prey on land-bound creatures that wander too close to bodies of water.
Jigglers almost always attack when they have the advantage. Using their camouflage, they surprise prey. They wrap their two long tentacles around their target and use the suckers on their smaller arms to anchor themselves on it, preferably in an area their pray cannot easily dislodge them from. Using the mucus sac on their backside, the creature will spray an acidic slime designed to weaken the skin (or in the case of mirelurks, their hard shell) and then use their sharp beak to bite into the skin. Using a specialized tongue, jigglers suck the blood of their victim, feasting on them until they have extracted enough nutrients. They then unlatch themselves and flee.
Jigglers prefer to escape conflict rather to engage in it. When in a situation in which they cannot immediately escape, they churn the mucus sac on their backsides and spray a less-concentrated acid into the face of their attacker, temporarily blinding them. If the creature finds itself in a situation where it cannot escape at all, it uses its two large tentacles as clubs.