Gothi

Gothi is a character seen in the movie adaption of How To Train Your Dragon. She is very small and does not speak in the final, on-screen product, although she had a much larger part in the earliest film concepts, when there was a lot of magic and things of that nature. Gothi 'speaks' by writing in the ground with her staff, in perhaps an old writing that few Vikings can read.

In the Film
It is her job to choose the most promising young Viking to fight the Monstrous Nightmare in the arena for the Final Exam, and if the child wins, he/she becomes a full Viking in the society She's the one who chooses Hiccup for the graduation ceremony in the movie, over Astrid. She is also seen comforting two children when the whole tribe is preparing for the battle at the Dragon's Nest.

In Riders of Berk
In the Riders of Berk TV series, she has currently appeared in two episodes. In episode 3-" Animal House", Stoick and Gobber go to her expertise to predict a major storm. She says yes referencing to Bucket's bucket which is said to predict bad weather. She has also appeared in episode 9-"Dragon Flower ". When the dragons are falling mysteriously ill, Gobber suggests to go to Gothi. She says (by writing with her staff) that the dragons are allergic to something new that has just come to the island, and tells them to get rid of everything that was new.

Trivia

 * Gobber appears to be the only one who can read Gothi's writing, he's the only person who has translated in the two episodes of Riders of Berk that she has appeared, Gothi says absolutely nothing in the film, she just gestures.