Modelengine mobs:
Orca:
eats all kinds of small fish, jumps above water with a splash, demands food if you hold salmon in your hand
White shark:
eats almost anything including humans, pulls the prey towards his jaws, has a chance to bite and leave
Moray eel:
creates a coral cave around him and hangs round it, hunts smaller fish
Sea krait:
hunts mostly small fish, venomous

Single Entity Item Mobs: (all of these are usable as statues and trophies)
Bat ray:
seabed animal, hunts crabs
Anchovies:
form groups holding tightly together, changes model on less fish each hit
Flying fish:
spawn in groups but flee predators airborne in all directions
Sailfish:
fastest predator, hunts all small and medium fish
Seahorse:
stays quite low, usually in pairs with babies, emissive
Lionfish:
venomous, does not attack
Blue sea dragon slug:
venomous, hunts all jellyfish
Cockle clam:
seabed creature, food for everything else

• Loot items:
  small, large and medium fish meat
  pile of shells
  shark fin
  potent venom
  shark meat
  whale meat