Antagonist

Character Role Analysis

VN

This only works if you think that VN is some kind of mastermind/author-God controlling Pnin's every move. If you read the Narrative Technique section, you'll know that possibly Nabokov created VN as a sort of evil author. Just like Nabokov created this story and as dictated the lives of the characters inside, you could think of VN as the author of Pnin's life.

In that case, it's not hard to see VN as the antagonist. Literally every single terrible thing that happened to Pnin could be his fault. Which just goes to show that authors are the ultimate antagonists.