Who is Balder from Going Bovine and what is their importance?

Balder is a garden gnome who comes alive at a house party. He claims to be a Norse god who has been turned into yard art. Cameron sets Balder free and Balder becomes his loyal servant in return. Balder is a sage warrior and a valiant fighter. He is virtually indestructible and loves to challenge people to try and kill him. Balder and Gonzo have a love/hate relationship and the three guys form a solid friendship by the end of the book. Balder is killed by a branch of mistletoe while the boys are visiting the beach.