|“||You'll need some backup. Sound the Great Horn and the Vikings of Berk will swarm to your side.||”|
It is unknown when the Great Horn was created or by who.
After the player talks to Mulch about a group of Dragon Hunters that are dangerously close to the School of Dragons Island, the latter suggests sounding the Great Horn in order to call for backup. The player does so and Hiccup immediately arrives with Toothless, ready to accompany him/her.
The Great Horn is a big metal horn that is suspended with two chains from a support made up of two pieces of wood, one vertical and one horizontal. The vertical piece is fixed onto a small planform, which is right underneath the horn.