The Deacon Shark is a creature that appeared in Prometheus: Fire and Stone. The creature largely resembles a Deacon with its protrusible jaaw, blue color and its overall appearance.
The Deacon Shark is a large carnivorous aquatic species that possess double jaws like a Xenomorph but in the similar style of a deacon as it has gums like them and protudes in the same way but whereas the Deacon only has one jaw with gums and teeth extending, the shark has two jaws. It appears in issue two of Prometheus: Fire and Stone where a group of them attacked the crew of the Helios, most of them are shot dead by the armed members of the crew. 
The concept of a Deacon Shark is somewhat ironic given that the design of the original Deacon in Prometheus, specifically its protrusible jaws, is highly similar to and was likely inspired by various shark species, such as the goblin shark (Mitsukurina owstoni).