Lyra Silvertongue, previously and legally known as Lyra Belacqua, was a young girl from Oxford in Brytain. Her dæmon was Pantalaimon, who settled as a pine marten when she was twelve years old.

Does Pan ever settle His Dark Materials?

In The Golden Compass, the first book of Pullman's trilogy, we first meet Pan as a moth. Eventually, Pan settles as a pine marten (I know, random). When kids pass through the threshold to adulthood, their daemons solidify. Daemons say a lot about their companions' personalities.

Why does Pantalaimon settle as a pine marten?

They no longer like each other very much. And because Pantalaimon is part of Lyra — her soul, taking the form of a pine marten to whom she can talk — that means she no longer really likes herself.