The title is a play on the 1777 song "A-Hunting We Will Go".
It’s Halloween and Daffy Duck’s nephew goes Trick-or-treating as a witch, in the same outfit that Bugs Bunny wore in Broom-Stick Bunny. He soon visits Witch Hazel’s house. He runs home after being scared by Witch Hazel’s hideous face (however Witch Hazel’s skin is white instead of green). At home, Daffy's nephew tries to explain to his uncle that he saw a witch. Daffy gets angry at his cousin and explains him that "there is no such thing a a witch, and that she’s just a poor old lady trying to get along". He tells him that he’ll prove it by meeting Witch Hazel.
Back at Witch Hazel’s home Hazel complains that "all she does is work in front of a hot stove making potions" and that she needs a vacation. But she must choose someone to take her place. Speedy Gonzales comes and asks for a cup of cheese. At first, Hazel complains but soon gets an idea. She spikes a piece of cheese with one of her special brews and feeds it to Speedy. Speedy turns into Witch Hazel and the real Witch Hazel asks him if he can act like her. Speedy, who is quite calm about this, says okay and runs around the house yelling his usual “Ándale, ándale, arriba, arriba, arriba, epa, epa.” Witch Hazel says he still acts like himself but it will do. She takes off to Hawaii, leaving Speedy to take care of the shop.
Then Daffy comes over and Speedy welcomes him in. Speedy makes tea out of Witch Hazel’s potions, leaving Daffy alone. Daffy, a little frightened, stays in the house stating that "she can be somebody’s mother, or father, or something". Speedy, still disguised as Witch Hazel, gives Daffy tea, turning him into the flower creature from Duck Amuck. Hazel then comes back from Hawaii and, after seeing what Speedy has done, disgustedly turns him into a mouse again. She then sees Daffy and gets in a mood for a duck dinner. She then turns Daffy into his old body. Daffy immediately runs away from Hazel. She catches him on a broom. Daffy jumps off her broom and parachutes down but the parachute turns into an anvil. Witch Hazel laughs until she runs into a rock.
Down on the ground, Daffy gets scared of another witch, who turned out to be his nephew in disguise. His nephew asks him if he saw the witch but Daffy just tells him that "she's just some creepy old lady trying to scare people, and that witchcraft is just a myth, an old superstiton". On the way home Daffy turns back into the flower creature from Duck Amuck.
As with the other Witch Hazel cartoons, June Foray voices Witch Hazel while Mel Blanc voices Speedy Gonzales, Daffy Duck, and Daffy’s nephew. This is the last Looney Tunes cartoon featuring Witch Hazel, as well as the last Looney Tunes cartoon with June Foray's voice acting in the Golden Age. However, she would reprise her role as Witch Hazel once again in an episode of the 2003 Duck Dodgers series.