Saddle

Saddles were used Vikings when they rode creatures such as horses and Dragons.

Dragon Saddles
When Toothless lost his left tail fin after a dragon attack on Berk, Hiccup made a new tail for him. Along with the tail, Hiccup also made a saddle for himself to allow him to ride him for hours. (How to Train Your Dragon

In Viking for Hire, after peace was made with the dragons, Hiccup and Gobber started to make saddles for the Dragon Training Academy riders and their dragon when they started to feel sore after riding their dragons for hours. However, Gobber added certain features to their saddles such as, horns, maces, catapults and even flamethrowers.

After 5 years, Gobber, Stoick and Hiccup started to make saddles at Gobber's shop for all the vikings and their dragons of Berk. (How to Train Your Dragon 2)