New mobs can be jellyfish, crab, octopus, whales, starfish, seahorse and sting rays all different variants and types
Jellyfish can sting you and have a chance of stunning you where you can’t move. They can glow at night and can change colors. When killed they drop Jellyfish tentacles and glow sticks that you can throw and pick back up to expel light. They spawn right below the top of the ocean. Hostile
Crabs pinch you if your too close to them. They go on land and underwater. When slain, they drop raw crab meat and when the babies grow up they drop crab shell just like turtles drop turtle shell when they grow up. They spawn on beaches and on the bottom of the sea. Neutral
Octopus can hit you with its tentacles and had a chance to grab you. When you are grabbed you can also have a chance to lose air quicker. The effect for losing air quicker underwater is called loss of breath. Octopuses can blend into surroundings. When killed, they drop raw calamari and octopus brain. They spawn in underwater ships, ruins and coral reefs. Neutral
Whales can shoot water out of their blowholes. They will swim away when attacked. They spawn near iceberg islands and cold oceans. They drop whale teeth when dead. Passive
Starfish are creatures that if attacked will stick to you and suck some of your life away. They have a chance to poison you when attached. They can change colors and stick to underwater buildings. Drops a sea star arm. Neutral
Seahorses spawn in kelp forests and can stick to the kelp with their tails. When you attack them, they swim away very fast only staying in the kelp forest trying to lose you. Drops kelp and seahorse fin when killed. Passive
Stingrays will be creatures that swim on the surface on the sea and will sting you if attacked. It drops stingray tails. Possibly rideable. Neutral
Dolphins should be able to blow water out of their blowholes just like whales they can possibly jump and blow water out of their blowhole too. When they die they drop raw cod and Dolphin dorsal fin. Neutral
When a sea star arm, jellyfish tentacles, seahorse fin, whale teeth, crab shell, dolphin dorsal fin, heart of the sea, ink sac and octopus brain are in a crafting table together, they make the amulet of the underwater life. It makes you do 1.5 extra damage underwater to any mob.
Guardians should be able to hit you from far away with its spikes.
Elder guardians should spawn guardians as a shield around it to protect its self after it gets hit for the first time. After its health is around 50 percent, it starts spawning underwater creatures to kill you no matter if their passive or neutral but it still spawns guardians to protect its self. It has a 50 percent chance when it dies to give you an effect but, if you are wearing the amulet of the underwater life, the chances of getting this effect is now 75 percent. The effect is called salt water eyes. Any near by underwater mob is aggressive towards you and you have red on the side of your screen until the effect was gone.