Harriet Hook is the eldest daughter of Captain Hook and the older sister of Harry & CJ Hook. She was introduced in the book, Isle of the Lost: A Descendants Novel. She had her pirate crew who are children of Captain Hook's pirate crew.
Harriet is described to be sassy and mean-spirited. However, she seems to have a caring side for younger children, including her siblings. When Ginny Gothel asked Harriet if she was going to make a transfer application to Auradon Prep, she was hesitant, saying that on one hand, her sister CJ liked it there, but on the other hand, her brother Harry wouldn't leave without his crew. This may imply that Harriet usually takes her siblings into consideration when it comes to important decisions. When Harriet decided to grab a transfer form for herself, she also grabbed two more for the Smee twins, Squeaky and Squirmy, as she thought that they'd want to apply as well.
Harriet bumped into Mal while walking through the bazaar. She asked Mal about the Auradon Prep roundtable meeting. She said that her sister CJ kept bugging her to go, but she had a big test with Queen of Hearts so she couldn't come. After a brief talk, Mal began walking away, but Harriet stopped her, reminding her that she was supposed to head in the opposite direction. Harriet probably left afterward.
Sometime later, when the transfer applications to Auradon Prep arrived at Dragon Hall, Harriet grabbed a form for herself, and two more for the Smee twins, whom she'd babysit that night.
- In Descendants: Wicked World, there is a character named CJ Hook, who's also the daughter of Captain Hook. In Descendants 2, Captain Hook also has a son named Harry.
- It's revealed in Rise of the Isle of the Lost, that they are siblings, with Harriet being the eldest, then Harry, and finally, CJ is the youngest.
- In Descendants 2: Uma's Wicked Book: For Villain Kids, it's revealed that Harriet participates in Croc Wresting Club. It is implied that she often wins as Harry stated that when it comes to placing bets with Sammy Smee, it's safest to go with his sister.