At the end of the trilogy, as Lyra is entering adulthood, Pantalaimon finds his final form when Will Parry touches him, and is later described as a beautiful pine marten, red-gold in colour with a "patch of cream-white fur" on his throat.

What animal does pan become?

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.

What does Lyra's Pan settle as?

Her dæmon was Pantalaimon, who settled as a pine marten when she was twelve years old. During her childhood, Lyra had the unique ability to read an alethiometer without formal training.