Sixteen-year-old Feyd, the younger nephew and heir of Baron Harkonnen, is described as dark haired, and "round of face and with sullen eyes".

Ari Szporn of Comic Book Resources wrote, "Both [Paul and Feyd] are charismatic, cunning young noblemen who have received the greatest education and combat training.

There was a sharpness to the boy that the Baron enjoyed ... a ferocity ... A year or two more — say, by the time he's seventeen, I'll know for certain whether he's the tool that House Harkonnen requires to gain the throne.

[1] Margot also intends to "plant deep in his deepest self the necessary prana-bindu phrases to bend him," which she later refers to as the "hypno-ligation of that Feyd-Rautha's psyche."

Presumably he is thus "prepared" and made vulnerable to a command which will cause complete muscle paralysis, a technique the Bene Gesserit sometimes use on individuals who are considered highly dangerous.

[3] Feyd's ambition and impatience to inherit the Baron's title and power spur him to attempt his uncle's assassination.

The attempt fails, prompting the Baron to reveal to his nephew the lofty plans he has for him, possibly to even have him ascend the throne as Emperor.

[1] As Paul makes his final bid to usurp the Padishah Emperor's power, he is challenged by Feyd, the current Harkonnen leader after the deaths of the Baron and Rabban.

Though famed for his prowess in single combat, Feyd intends to guarantee victory by breaking the formal rules of kanly (which govern this type of challenge) and using a hidden poison spur in his fighting outfit.

The Bene Gesserit, desiring a son by Abulurd for their breeding program but finding Glossu unacceptable, secretly administer fertility drugs to an aging Emmi, who soon conceives Feyd.

[9][11] Emmet Asher-Perrin of Tor.com called his portrayal "the strangest casting choice you've ever seen," adding that "it's also hard not to love the strangeness of it.