“Randall from Monsters University
Yes in Monsters Inc he was bad but in MU I genuinly felt bad for him. He was the shy and awkward kid looking to make friends and study hard. He was as nice and friendly as he could to Mike and helped out when Mike was studying like a mad man. But as soon as Mike started hanging out with Sully, he left Randall.
So Randall not having any friends, he goes out and joins a fraternity thats willing to take him in. They then slowly corrupt him into the bitter and evil Randall we know now.
He quite the tragic character” – u/Bashful_Bayleef