Some quotes that portray Abigail as the most despicable character are:
"You loved me, John Proctor, and whatever sin it is, you love me yet!"
Abigail has had an affair with her former master John Proctor. As a member of the household, she was fired by Proctor's wife.
"I saw Sarah Good with the Devil! I saw Goody Osburn with the Devil! I saw Bridget Bishop with the Devil!"
She accuses other women of the practice of magic - witchery.
"I beg you, sir, I beg you—see her what she is. . . . She thinks to dance with me on my wife’s grave! And well she might, for I thought of her softly. God help me, I lusted, and there is a promise in such sweat. But it is a w...’s vengeance..."
Proctor confesses in trial his past affair with Abigail, and declares that she is seeking revenge on him for ending their relationship.