Requesting a Hostile Fantasy Shark That Hides Itself

*Note*: I know Mojang is against adding regular sharks, but this fantasy shark will look almost nothing like a normal shark, and neither act like a normal shark.

Apart from the Drowned there are little threats in the wide, vast oceans. Guardians and Elder Guardians are isolated near their Ocean Temples, which sparsely populate the ocean floor, and Dolphins are neutral mobs, not hostile. A hostile mob that hides and camouflages itself, instead of chasing you as the Drowned does, would be a great addition to the ocean floor, since why should only the Overworld land have all the monster variety? These fantasy "sharks" would be as flat as a flatfish, with both eyes on one side of their bodies, but with the teeth and ferocity of a sand shark and the patterns and tail of a catshark. I couldn't create a name for these creatures, so I'll refer to them as creatures. With 20 health points (10 hearts) and 2-3 blocks in length and 3-4 blocks in width, these creatures would normally hide on the ocean floor, laying in wait for a player to swim past before lunging out and attacking them with lunging bites. Once the creature attacks the player it becomes a fight to the death (or a fight to the chunk load), as the creature won't hide again until the player dies or the player leaves the chunk. When hidden on the ocean floor they camouflage themselves perfectly with whatever block they are on, but they do stick out by 1-2 pixels from the ocean floor, so a player with a keen eye can spot them. Often found in sandy areas, due to them having the colouration of a catshark, they are found on the floors in forests of kelps, near beaches in shallow water, and among coral reefs in warmer waters. They are not found in colder water (Cold and Frozen Oceans), however different variants with different skin colours and patterns could be found in deeper and different waters, such as a grey variant living in deeper ravines where there's stone or a brown variant found upon dirt sea floors. They would drop fish upon death, as well as several blocks of whatever block they were hiding on. It also gives more use to the Impaling enchantment as it would help take down this beast.