Sarcastic fringeheads are the largest of all fringeheads and they can grow as long as 30.0 cm in length, fringeheads are typically found in a demersal, marine environment. They occupy depths of up to 60 meters.
As suggested by their name, sarcastic fringeheads are extremely temperamental. They are fiercely territorial creatures that aggressively protect their homes from all intruders, regardless of size. The majority of the time, sarcastic fringeheads are at rest in their homes , only their heads protrude. However, upon the first sign of danger, they will employ their enormous mouths and needle like teeth for defense. Initially, they emit only a warning accomplished by the flexing and snapping of their jaws. If the intruder ignores the warning, they will use their ferocious teeth to attack
source:university of michigan museum of zoology