Quarrel appears as a cohort in Storm of Zehir.
Stats
Quarrel is a Chaotic-Evil Half-Drow Sorcerer.
Recruitment
Quarrel can be found in West Harbor. You need to complete West Harbor - Path of the Master, to recruit him.
Gameplay
Strength 10 / Dexterity 20 / Constitution 12 / Intelligence 12 / Wisdom 10 / Charisma 16