The Bobbit worm will give you anxiety.
The worm, specifically, is an aquatic predatory polychaete worm that dwells on the ocean floor. It tends to “ambush” its prey, using a lightning-fast striking method
The worms can grow to a size of about 10 feet, found primarily in the Indo-Pacific and Atlantic. But they can get accidentally introduced into fish tanks and aquariums.
They bury themselves in loose gravel and sand around coral reefs before pouncing.
As you can see, their jaws are quite powerful.