Frost had never lost a battle prior to his defeat at the hands of the five Guardians. Since then, Frost had sworn revenge and devising plans for the Guardians' demise. In combat, he rides a large, green, rhinoceros-like mount named Crimson and wields a magical blade that can deflect enemy spells and fire energy blasts at his opponents. When the Veil was lowered, he accidentally found himself in Heatherfield. He took the opportunity to take revenge. The weakened Guardians defeated him rather by smartness than strength. He is currently imprisoned in the Tower of Mists.
In the animated series Frost the Hunter was a high-ranking member of Phobos' army. Frost makes a cameo in "Ambush at Torus Filney" but his real debut is in "Framed" where he and his mount three-horned rhino, Crimson, go to Elias Van Dahl's painting to defeat the Guardians who are trapped in the painting. The girls, who can not transform, try and escape Frost with help from Elias by painting escape routes, but when Cedric and the Lurdens join him the situation looks desperate. Irma and Caleb eventually enter the painting and they use their jousting skills to defeat Frost, Cedric and the Lurdens.
In "A is for Anonymous", Frost learns that Elyon has become the new ruler of Meridian so he uses his last magic from Phobos to go to Earth and glamour himself as a human. He is able to capture Irma, Cornelia and Hay Lin in a sphere of magic and threatens Taranee to bring Will to him and give him the Heart of Kandrakar. His plan backfires and Will uses the Heart to free the others and in Guardian form, the five easily defeat Frost and Crimson. For their humiliating defeats, Frost and Crimson join the Knights of Vengeance.
Frost challenges leadership to the Knights but Raythor outsmarts him in a mini-battle. He participates in all the Knights' activities proving to be a useful member, along with Crimson. Frost lacks intelligence and is a downright brute, showing his unintelligence by Crimson being the rhino's name when he is black-green. Frost is also very impatient, has a short temper and never thinks before he acts. In "J is for Jewel", he helps release Prince Phobos but when Elyon returns from her meditation, she defeats Phobos, with Frost and Crimson being one of many imprisoned in the Infinite City.
In "O is for Obedience", Frost is mad at learning Nerissa was the Mage all along and that she was not interested in their vengeance. Frost even considers telling the guards this information, when he learns out they know. Frost and Crimson reappear in "X is for Xanadu" when Phobos breaks his oath and frees all his minions too. Both help fight for Phobos in the Battles of the Infinite City and Kandrakar.
In "Y is for Yield", Cedric betrays Phobos and eats him whole, gaining all his powers. Frost decides to bow down to Cedric and Miranda, and is put in charge of defeating the rebels. However the Guardians eventually win and both Frost the Hunter and Crimson are imprisoned again in the Infinite City. Frost is actually the only member of the Knights of Vengeance who remains loyal to Phobos, who does not either betray him later or die - as Miranda, Raythor, Sandpit and Gargoyle all betrayed Phobos and Tracker was killed in battle.