Here's the opening to the Planet of the Beast King (Jyu-Oh-Sei) YouTube - Jyu-oh-sei Opening The people in the countdown are Thor, Tiz, Third, and Zagi or something. Thor and his twin brother, Rei get trapped on a foreign planet after the mysterious murder of their parents. The twins find themselves with a group of outcast children and their leader. They learn the ways of the planet. Most of the planet is inhabited by plants and humans are a minority species that have to struggle to survive and not be eaten by plants. But, Rei ends up getting eaten by a plant leaving Thor all alone to discover his true identity. Thor ends up becoming leader of his pack and later falls in love with a girl named Tiz. They promise each other that they will have an offspring together.
There's only sixteen episodes in the series.