Yezzan zo Qaggaz is a character that will debut in the fifth season. He is a slave-trader from the city of Yunkai, on the coast of Slaver's Bay, and one of the Wise Masters, the ruling elite of the city.
In the books
In the A Song of Ice and Fire novels, Yezzan zo Qaggaz has yellow eyes and is so morbidly obese he can no longer stand. He contracted a jungle disease while on a slaving raid in Sothoryos which he has been suffering from for years: he cannot hold his water so he always smells of urine, which even perfume cannot hide. He wears yellow silk tokars with gold fringe. He is obsessed with the grotesque and often purchases slaves with physical deformities to add to his "collection". While overweight he is still shrewd and intelligent, a trait some of the other Wise Masters don't share.
Despite his personal grotesqueness, it is remarked that Yezzan isn't that bad compared to some of the other slavers, and isn't particularly cruel. So long as his slaves obey Yezzan treats them relatively well, and makes sure that they are well fed and looked after (though this is in the same sense that a man will make sure that Horses he owns are well fed and are not beaten, because he doesn't want to needlessly damage his own valuable property). He is also one of the few Wise Masters who urges that Yunkai should try to make peace with Daenerys, fearing that further conflict with her Unsullied army and increasingly large dragons is more trouble than it is worth.