Hody Jones is a fishman who grew up feeding on hatred of humans, inspired by Arlong. However, unlike him, Hody never received any harm from humans. He hates them and wants to eradicate their race for no other reason than simple racism. Also, unlike Arlong, Hody has no qualms about harming a fellow fishman, mainly the ones who are friendly to humans.
His hatred for humans is so fierce it brought him to murder his own Mermaid Queen Otohime and accuse a human, to make all Fishman Island hate them.
Years later, Hody decides to take over Fishman Island with his crew and his newfound ally Vander Decken. He rapidly gains power, as his coup d'état was prepared with every detail. All but one: The Straw Hats.
Hody is a powerful fishman, and masters the Fishman Karate in a murderous way. He also took steroids, which changed his appearance and empowered him with many side effects that came after his defeat to Luffy.
As the events of One Piece got more and more serious over the years, the villains became worse in result. And Hody ranks among the worst villains of this universe, to the same level as Akainu.
Hody Jones is a complete psychopath, who is filled with hatred toward humans that he killed Queen Otohime for wanting to be their friends, and ruined all her efforts by accusing a human. He is also willing to kill her daughter Shirahoshi, whom he mocked for feeling no grudge toward him.
What makes him worse than many One Piece villains like Arlong is that, unlike them, he has no excuse and no principles. He hates, torment and kills humans for virtually no reasons at all, and has no qualms about doing the same to anyone regardless of species, which unlike Arlong also includes his own people. Because of this, Hody is arguably one of the most evil characters in One Piece.