Gothi's Frostfright (or simply Frostfright) is the name given to the Snow Wraith that attacked Gothi when she was in an expedition on Glacier Island during her youth. Its name was first revealed in Dragons: Rise of Berk.
Gothi first met this Snow Wraith as a "young" girl, when she became the sole survivor of its attack on her search party. She still has the scar from the attack on her arm.
This Snow Wraith was encountered by Gothi when she was a young Viking. She had visited Glacier Island in search of pure glacier water known for its healing properties. Gothi's Frostfright attacked her entire search party. Gothi tried to defend herself by hitting it with her staff, but the Snow Wraith bit her and flung her into a heap of snow. Because she was hidden by the cold snow, the Snow Wraith could not detect her and left her as the only survivor of the team. Gothi returned to Berk safely but was scarred physically and mentally.
The Dragon Riders came to Glacier Island to find a tooth from a Snow Wraith, which was the key to unlocking the Dragon Eye. Frostfright first appeared during a blizzard that hit, using the weather and its abilities to strike at the group. With what he observed from the attack, Hiccup realized the Snow Wraith could only see body heat since it didn't attack Snotlout when he was buried in the snow or Gothi the she fell into a snowbank in the past.
The gang set up decoys to trick Frostfright by setting dummies on fire. It appeared to work until Snotlout accidentally had Hookfang trap them in a cave. Only Hiccup and Toothless made it out, leaving them exposed. The two tried conceal themselves in the fires, but this did not work; Frostfright was able to tell which targets were real. Gothi, after getting out of the cave, used her staff to attack the dragon, but it quickly flung her aside. The other dragons surrounded the Snow Wraith, causing it to take off. However, one of its teeth was embedded in Gothi's staff, allowing the dragon riders to complete their task.
Later on, the Dragon Riders encountered three Snow Wraiths, including Gothi's Frostfright, in an ice cave after they were trapped by the Dragon Hunters. When Tuffnut accidentally woke them up, the Dragon Riders did their best in holding their ground against the pack. The Snow Wraiths started flanking them by burrowing in and out the cave's walls and firing blasts at them. Toothless managed to hit and stun one of the Snow Wraiths, but the others carried it to safety and burrowed out of the cave through the ice.
Ryker and the Dragon Hunters managed to capture the Snow Wraiths, but the Dragon Riders came to their rescue, and they were relocated to a safer place on another island.