Frog

       Once a Guardia Knight, Frog's real name was Glenn. He used to be the student and close friend of the legendary Knight, Cyrus. 
       Glenn was caring, noble and kind to people even to those who oppress him.  He was a great swordsman and probably even better than Cyrus but he didn't like fighting thus never used his talents to the full. He journeyed with Cyrus to battle Magus into the forests and there he saw the death of his friend. Cyrus' last words to Glenn was to always protect the Queen. Here Glenn kept his promise by saving the queen in the hands of Yakra. 
       Magus didn't kill Glenn and instead turned him into a creature of a  spineless nature. Since then, Glenn  trained himself to be a better swordsman and used his talents to the full to protect the weak and oppressed. He didn't want to confront Magus again because of painful memories and because of the loss of the Masamune, a magical sword which was used by Cyrus and was Magus' weakness  but  was split into two during the battle. Crono and his friends looked for the other half of the Masamune sword and and fixed it using the help of Melchior and by finding a dreamstone in 65,000,000 B.C. 
       When the Masamune was handed back to Frog whole and intact he was able to get the courage to confront Magus again. He agreed in helping Crono in search for the dark wizard. 
        Frog  encountered Magus once more and with the help of Crono and his friends, they fought the evil wizard. Frog wasn't able to kill Magus at that time but was sucked into a time portal the  wizard created. 
      Eventually, Frog forgave Magus and gave up the idea of avenging his friend's death for he thought that killing a person wouldn't bring back the life of another.
      During his journey with Crono, Frog was told to visit a haunted building in his time. Frog discovers that Cyrus was the one haunting the place and was able to talk to his friend one last time. Frog comforted Cyrus by telling him that their queen was in safe hands with him which set his soul to peace. 
      Suddenly, the Masamune which was watching Frog all this time came to life and took it's real forms: Masa and Mune. They said that they have been waiting for a true Knight like him to become the holder of the sword. The Masamune became even more powerful than before now that Frog was it's new owner. 
      Frog now felt ready to help Crono and confront his true enemy, Lavos, which threatens to destroy them all. He learned Water Magic along the way.