Dragon Manual

The Dragon Manual is a Viking encyclopedia of all dragon species discovered by the Hairy Hooligans tribe. Considered an important piece of knowledge, it is how the Vikings of Berk know the weaknesses and methods needed to take down some of their reptilian attackers.

Language (in film)
The language used in the dragon manual consists of a language that vikings in Berk use to read and write. Some letters share the same symbols such as w, v, u, o, and y; e and i; s and ;, etc. The language lacks punctuation and some letters such as the letter x (using "cs" or "ks"). Few letters, such as the letter q, are unidentifiable because it's not mentioned in the film. Other text consist of symbols that have no meaning or organization. Other than the film, the language appears in animated webisodes.

List of Translations
中文- Mandarin

危险度高- extremely dangerous

格杀勿论- kill on sight

烧死受害者- burns its victims

活埋受害者- buries its victims

掐受害者- chokes it's victims

把内脏全都挖出来- turns it's victims inside out

In film

 * Extremely dangerous
 * Kill on sight
 * Burns its victim
 * Buries its victim
 * Chokes its victim
 * Turns its victim inside out


 * Skrill
 * Rides lightning bolts like an air torpedo in the sky
 * Thunderdrum (spelled "Thunderdum" in film)
 * ​This reclusive dragon inhabits sea caves and dark tidepools
 * When startled the Thunder Drum produces a concussive sound that can kill a man at close range.
 * Timberjack (spelled "Timberjac" or "Timberjak" in film)
 * This gigantic creature has razorsharp wings that can slice through full grown trees
 * Scauldron (spelled "Scalldron" in film, more reasonable due to the word scalding meaning burning hot)
 * Sprays scalding water at its victim 
 * Gronkle, Hideous Zippleback (spelled "Zippelbac" or "Zippelbak" in film), Deadly Nadder, and Whispering Death
 * Night Fury
 * Speed unknown
 * Size unknown
 * The unholy offspring of lighting and death itself. Never engage this dragon
 * Your only chance: Hide and pray it does not find you
 * Make sure you see it before it sees you so you can have time to hide. 

​In animated webisodes*
​*All text in the film appears in the online animated webisodes.
 * ​These claws are very powerful, one claw can easily support the creature's weight. They have been known to rip through old norse, maple bark. Not a small task to put it lightly
 * ​Referred to as (Glaacs, Claags, Claacs, or Glaags) (Thorn, Thurn, or Thyrn) named after the great warrior, may he rest in Valhalla

Dragons In The Book

 * Stoker class
 * Monstrous Nightmare
 * Fireworm
 * Terrible Terror
 * Typhoomerang
 * Tidal class
 * Scauldron
 * Thunder Drum
 * Oceanzap
 * Bewilderbeast
 * Strike class
 * Night Fury
 * Skrill
 * Sharp class
 * Deadly Nadder
 * Timberjack
 * Speed Stinger
 * Mystery class
 * Changewing
 * Boneknapper
 * Smothering Smokebreath
 * Fear class
 * Hideous Zippleback
 * Snaptrapper
 * Boulder class
 * Gronckle
 * Whispering Death
 * Screaming Death
 * Unclassified
 * Grapple Grounder
 * Flightmare
 * Cloudjumper
 * Seadragonus giganticus maximus

Role In The Film
The Dragon Manual is given to the students of Dragon Training in order for them to study up on the dragons they will be facing in future sessions. Apart from Astrid and Fishlegs who have already read it, the rest of the group don't appear to be keen to study the Manual.

Later on that same night, Hiccup returns to the village hall to try and find any information on Night Furies, hoping to use the book to try and approach the one he shot down. The Manual proves to be fruitless, only warning him that Night Furies are considered too dangerous to try and kill and should be avoided at all costs.

In Book of Dragons, Hiccup is shown doing the major re-write and update of the Manual, assisted with the personal observations his friends have made with their own dragons

Errors
As it is displayed in the movie, the Dragon Manual has many errors throughout it.
 * Though Hiccup pronounces the dragon's name Thunder Drum, the book has it written as Thunderdum.
 * On the second page of the Thunder Drum, the two lines written consist of "This reclusive dragon" four times on the first line, and "Inhabits sea caves" four times on the second line.
 * The Scauldron's page in the dragon manual has a line from the Timberjack's page. "This gigantic creature has razor sharp wings that can slice through full grown trees."
 * All of the dragon pages have 'Extremely Dangerous, Kill on Sight, Kill on Sight' where we would normally expect the text Hiccup is reading, most often multiple times across the page.
 * After Hiccup reads off the four ways the dragons kill people (while the camera is on him) the second page he lands on has three red drawings and two labels. The label on the left reads 'Extremely' and the one on the right, 'Dangerous'.
 * A picture of the Deadly Nadder appears on the opposite pages of the one the camera is pointing at several times.
 * Several images of vikings killing the Thunder Drum, Scauldron, and Gronkle appear several times.
 * As a fill-in, the extra text, translating as only the traditional Elder Futhark/Anglo-Saxon alphabet, is displayed in mirror image.

TV Series
The Dragon Manual is used many times in the series when the Riders meet new Dragons, but it is instead refered to as the Book Of Dragons. Mostly Hiccup and Fishlegs revised the book.

The book played an important role in Heather Report Parts I and II, when Heather steals the book for the Outcasts in exchange for her parents.

There are new dragons discovered that have not been documented in the Dragon Manual.

through the TV Series several images from the Dragon Manual.

Trivia

 * The original line 'Kill on sight' came from Gobber's great-great-great grandfather named Bork the Bold who was unfortunate with dealing with dragons.
 * The language used in the film is a modified version of a mix between Elder Futhark/Anglo-Frisian runes and English. It also shows very close resemblance to Khuzdul, the fictional Dwarfish language in the Lord of the Rings and the Hobbit.