Sven is Kristoff's best buddy. He was first seen at the beginning of the film playing with Kristoff, they were both young then, and Sven was a young reindeer. They were soon adopted by a group of trolls.
The second time he was seen was during the opening of the gates for Elsa's coronation, where he and Kristoff shared a carrot. Next was when Kristoff tried buy a carrot for him at the "Wandering Oak's Trading Post" and that is where their journey with Anna began.
