The Subtle Knife
Ruta Skadi is the Latvian witch queen, and a lover of Lord Asriel. Her dæmon is a bluethroat named Sergi. She is 416 years old in "The Subtle Knife", and makes appearances in "The Subtle Knife" and "The Amber Spyglass". Her second name, "Skadi", is also that of a Nordic winter goddess.