The great-nephew of Gravity Falls's most powerful man, Dipper Northwest (Snowflake) is at the top of everything from top of his class to top of the social scene. Fiercely loyal to a select few, he tends to set himself apart from others despite almost always being surrounded by peers vying for his attention. His arrogant attitude is apparent to all who meet him, although most tend to ignore it in favor of focusing on his popularity and family name.
He adores his great-uncle, Stanford, and while he would do almost anything to please him, Dipper's first priority will always be his sister. He is very protective of Mabel due to him being under the impression that she's so ill that she can't even leave the Northwest estate. He hates gossip, especially when it's focused on Mabel, so he would do whatever it takes to shut down anything potentially slanderous concerning her.
Despite his impressive intellect, Dipper is frustratingly ignorant to important magic-type things occurring around him, in front of him, and even inside of him. Always set in his ways, it's hard to convince Dipper to change his mind about something when he believes himself to be correct. His stubbornness gets the better of him by blinding him from the obviously supernatural unfolding in nearly every part of his life up until he literally summons zombies on accident/purpose. Oops.