This is Spinosaurus, a highly dangerous and aggressive prehistoric spined lizard.

He was frozen in an ice block over 100 million years, but after the ice thawed out, he killed an adult humpback whale.

And after that, he's delight in eating animals like large aquatic animals, humans, fish-men and merpeople for food.

But his main target is Aqua, who's using her Growth Hairpin to grow match into Spinosaurus' size and strength. After being defeated by his prey, a giant mermaid, the Spinosaurus seeks his revenge and wants to eat her.

In the final battle, Spinosaurus later appear again in the climax when King Ryujin is trapped in a cave after he stomps on the top of the cave.

When Aqua and her friends come to Ryujin's aid, Spinosaurus hunts Aqua down into the depths of the water as she tried to save her father.

Aqua manages to escape Spinosaurus who continue pursuing her, And then she tricks him into hitting a log wedged beside a large rock. This causes the giant rock to fall down and crush the giant vicious reptile to death in the process, which also frees Ryujin.

But then ptscreatureverse suggested Spinosaurus did not die and just be seriously injured and eventually nursed back to health instead.

He also said the dinosaurs were not destructive and bloodthirsty monsters just like in the movies, and instead, they were like any other animal living their life in ancient ecosystems. He also wishes that I give Spinosaurus a chance for it to survive and possibly be redeemed.

And so, I've decided to letting him live. And PTsCreatureVerse was delighted to hear it, and he said "With enough care and hospitality, the citizens of the sea could have a very powerful ally in this Spinosaurus."

Yeah, after the rock injured his back legs, Aqua and Ryujin decided that he needs to be nursed in the Odyssey Island, where the Atlantean Human lives.

I hope you understand.

His villain role is similar to:
Cretaceous and Maelstrom (Ice Age 2: The Meltdown)
Sharptooth (The Land Before Time (1988))
Carnotaurus (Disney's Dinosaur)
Spinosaurus (Jurassic Park III)
Indominus Rex (Jurassic World)

And then heroic role is same as:
King Kong (Monsterverse)
Gamera (Heisei Trilogy)
Godzilla Jr (Godzilla: The Series)

Powers/Skills:
Highly Intelligence
Powerful jaws
Sharp teeth
Sickle claws
Strength
Stealth
Intimidation
Swimming skills
Hunting skills
Smell tracking
Speed
Endurance
Stamina
Agility

His Sound Effects mixing together with:
Spinosaurus (Jurassic Park III)
Carnotaurus (Disney's Dinosaur)
Indominus Rex (Jurassic World)

His design is based on the old concept of The Isle's Spinosaurus design - https://static.wikia.nocookie.net/i.....20200208141304 and make his legs more muscular, giving his crocodile tail spikes, and crocodilian colors.

I hope you're liking it.