Task: Question Answering
Input (English): Context: Ten-year-old Chihiro (voice: Daveigh Chase in the 2002 English dub) and her parents (voices: Lauren Holly and Michael Chiklis) drive to their new home. Chihiro is whiny and unhappy about the move, especially when she notices that the bouquet her friend gave her as a good-bye gift is wilting. In sight of their new house, they take a wrong turn and follow a bumpy, decayed old road through the woods; Chihiro sees an odd old statue through the trees as they drive by. The road ends at a tunnel leading to an abandoned theme park. It gives Chihiro the creeps, but her parents persuade her to go in with them and look around.After wandering across a grassy landscape and a dry riverbed, they climb a stone staircase and come to a street lined with restaurants and shops. Most are deserted, but the aroma of cooking leads them to the one restaurant that's well stocked with food -- though it's mysteriously deserted. Mom and Dad are hungry and start eating, despite Chihiro's objections. The food is delicious, and Chihiro wanders away to explore while they eat. She finds a towering, ornate building that she recognizes as a bathhouse (a spa resort); there's a train track running under it. She meets a boy (voice: Jason Marsden) in traditional dress who is alarmed to see her; he tells her to leave and get back across the river before it gets dark. Chihiro runs back to her parents, but they're still eating -- and they've turned into pigs. Strange, dark, ghostly figures appear in all the shops and streets, frightening Chihiro and separating her from the pigs that were her parents. Chihiro runs back to the river, which was nearly dry when they came over but is now full and large, and she doesn't even recognize the buildings on the far side. As a riverboat approaches, she notices that her body has become transparent.The riverboat lands a big crowd of people in costume -- or maybe they're not people; at first they're only visible as paper masks. Chihiro thinks shes dreaming, but can't wake up. The boy who warned her away finds her and tells her she must eat some food from his world or she'll fade away. He assures her that she won't turn into a pig. She swallows the morsel he gives her and becomes solid, but finds that she's stuck to the ground until he recites an incantation to release her. A bird with a woman's head flies above them and he hides her, saying the bird is looking for her. They run through alleys and the pig barn to the big bathhouse, which is accessed by a bridge; the boy says she has to hold her breath as they cross the bridge or the spell that makes her invisible will be broken. Customers -- fantastically varied gods and spirits -- are crossing the bridge and being greeted by bathhouse staff. Chihiro makes it almost all the way across, but a frog (voice: Bob Bergen) that speaks to her companion (calling him Haku) startles her and she takes a breath. Luckily only the frog seems to see her, and Haku uses magic to encase it in a bubble to shut it up.Haku tells her to find Kamajii (voice: David Ogden Stiers), the boiler man, and make him give her a job; she must have a job to stay at the bathhouse, or else Yubaba (voice: Suzanne Pleshette), the old witch who rules the bathhouse, will turn her into an animal. And Haku says she has to stay if she wants to find and help her parents, who are still pigs, wherever they are. He knows her name and says he's known her since she was very small.Chihiro descends a steep, winding, rail-less wooden stairway in search of Kamajii and the boiler room. When she finds them, she sees a weird set-up in which the boiler is fed by creatures like spiders (delivering coal one lump at a time) and the machinery is controlled by a bearded, bald man 
 Question: Who used the black slug to control Haku?
Output (English): yubaba