This shield is made out of three simple materials--Monstrous Nightmare scales, tar and driftwood. This shield is made by laying several planks together and binding them, before being covered with a layer of tar and Nightmare scales.
Because of the heat-resistant properties of the fire-loving Monstrous Nightmare, the scales are effective against heat coming from a specific direction. However, the scales might melt under high temperatures.
In "Dragon Down", the gang try to save Hookfang, who was hiding in a searing hot cave in a volcano. They collected the scales he was shedding and construct the shield under Hiccup's instructions. After it is complete, Snotlout and Hiccup enter the cave. Soon, the shield starts to melt, but held up just long enough for the duo and the dragon to escape.