Gothi

Gothi is a small woman, but the prominant "Elder" of the village. 

Before the dragons came to live on Berk, she was the one who got to pick the dragon trainee who would kill the Monstrous Nightmare. She also is known as the "spiritual" consultant on the island, predicting future events as well as healing with old Norse rituals as seen in the Riders of Berk.

In the episode Animal House Stoick and Gobber sought her help when trying to see if a early winter storm was coming. Although it was started she usually uses goose feet or chicken bones to predict such events, she just went off the logic of Bucket's bucket tightening to know there was a storm coming.

Gothi drawing with her walking staff in means to speak

In Dragon Flower Gothi returned to help the riders figure out how their dragons were sick where Astrid mentioned rumors that Gothi could tell when someone's going to die just by looking at their fingernails. Gobber debunked that theory, though, and said it was looking at someone's tongue instead.

Gothi is also apparently mute, and uses her walking staff to write words or draw pictorial representations of what she's talking about in the sand (or whatever can be written on nearby) to communicate. She must have a close connection to Gobber because he usually translates her drawings into words everyone else can understand, but even he can mis-communicate, much to Gothi's annoyance.

She lives alone, high up above the village on a house standing on tall rafters and rocks. It's a rather unstable place to live for someone so old, but she seems fine up there.

Gothi's House