Terror-Mail was an idea put forth by Hiccup and Fishlegs Ingerman together, considering how Terrible Terrors are especially territorial, they would fly back to their home from wherever they're released; therefore, notes were tied onto Terrible Terrors' legs and would be released so that they would take the message straight home. However, it was later used by many in the archipelago, though only a few can be seen putting this to use in Dragons: Race to the Edge. This method of communication was first named "Air Mail" by Hiccup only to be called "Terror-Mail" later, and even sometimes nicknamed "T-Mail".
In the two-part episode, "Edge of Disaster, Part 1" and "Edge of Disaster, Part 2", Johann used Terror-Mail to ask for help in saving his ship from Scardian's pack of wild dragons. At the same time, Astrid Hofferson asked for help from Berk in defending Dragon's Edge from Dagur's Berserkers and Ryker Grimborn's Dragon Hunters.
In "To Heather or Not to Heather", Fishlegs used Terror-Mail to secretly stay in contact with Heather.
In "Stryke Out", the Dragon Hunters have also taken use of Terror-Mail with their captured Terrible Terrors. During a dragon fight, one of the hunters was tricked by Astrid into sending a Terror-Mail to the hunters' arena to warn them about the Dragon Riders. The latter used this to their advantage to track Hiccup and Toothless down by following the Terrible Terror towards its designated destination.
In "Triple Cross", Hiccup receives a Terror-Mail from his father, requesting him to come alone to a specific island. Once there, he finds no one else but Viggo, to which he reveals he impersonated Stoick, in order to get Hiccup's help.
Terror-Mail appears in a player quest called "You've Got Terror-Mail", which is a part of the "Secret of the Leviathan" expansion.
Terror mail Terrible Terrors appear in this game, serving as a way for characters to communicate with each other and as clues for the player.
|“||It turns out those little flying fire-starters [Terrible Terrors] make for excellent messengers! All we have to do is scribble out a quick note, place it in the delivery pouch worn by a specially trained Terrible Terror, and send the little guy to relay the information to any number of drop points we've taught the Terror to locate. [src]||”|
|— Fishlegs Ingerman|
Communication: Terror-Mail is a messaging service used on Berk and around the archipelago where Hooligans travel. The use of Terrible Terrors to carry messages is also utilized by other groups and tribes, such as the Dragon Hunters. It is unclear which group adopted the practice first, or if it developed independently.
|Terror Mail uses Creative Commons Licensed content from the Dreamworks School of Dragons Wiki page You've Got Terror-Mail. The list of authors can be found on the page revision history (view authors).|