In the live-action adaptation, Whizzer was one of the original 15 puppies given birth to by Pongo and Perdita. When Horace and Jasper raided the Dearly's house to kidnap the puppies and bring them to Cruella De Vil, Whizzer took a bite at Jasper's hand as the Badun tried to reach out to grab him, causing Jasper to hit his head above on the counter.
When the van arrived in Suffolk and the Baduns went into a pub, Whizzer was able to wiggle out of the bag and bark to Kipper the Airedale terrier, who then informed the farm animals about this during the Twilight Bark. During the escape, Whizzer distracted Horace and Jasper; some cases being tricking Jasper into stepping on a loose floorboard and falling through it, or Horace slipping on some ice and flying out the window. He eventually escapes with Kipper's help and returns home.
In this version, it is said that Whizzer is amongst the bravest of the pups. Despite being very brave, he had a constant bladder problem, often urinating in places he shouldn't, hence his name. Another display of his bladder issue is when he's escaping from De Vil Manor and relieves himself on a fashion magazine, with Cruella's picture on the cover.
In the TV series, Whizzer's appearance differs to having white ears with two spots on his left ear, a red collar, grey eyelids and notable bags under his eyes. He is usually seen hanging out with Dipstick or Mooch. Usually, when seen with Mooch, he acts as a posse member, usually laughing about jokes Mooch makes and commenting them to be "good ones."
His bladder troubles are brought more to light here; various cases would be in "Twelve Angry Pups" when Mooch mentions Whizzer losing his bladder control, and "A Christmas Cruella" in which he is picked up by Cruella to hug and accidentally pees all over her. In "Dalmatian Vacation", during the journey, the puppy bus has to stop every couple of feet, because Whizzer is in desperate need to relieve himself. Cruella gets fed up with the time-wasting stops and refuses to let the bus stop again. However, she again made the bus stop after Whizzer relieved himself in Cruella's shoes.
As the Dalmatians take a tour of a "Kanine Krunchies" factory, they are told not to mark any territory during the tour. Whizzer gives the audience a look of disappointment.
Episodes where Whizzer has speaking roles
- "Love 'Em and Flea 'Em"
- "Bad to the Bone"
- "Purred It Through the Grapevine"
- "Cadet of the Month" (amongst crowd cheers)
- "Mall Pups"
- "Cone Head" (albeit laughing only)
- "Walk on the Wild Side"
- "Dalmatian Vacation, Part 1: Road Warriors" (Video CD version only)
Whizzer (based on his "live-action" appearance) appears as one of the main two Dalmatians in the PC game 101 Dalmatians: Escape from DeVil Manor where he, along with Patches, try to escape the Baduns and find their way out of the manor. Whizzer mainly serves as a guide the player talks to for hints, in case they get stuck on a certain puzzle. In the game, he claims that he is good at figuring stuff out and climbing items.
In 101 Dalmatians: Animated Storybook, on one page, three Dalmatian pups jump into a boot in the Dearly's lounge. While he may not be referred to by name, one of the pups comments, "Ewww, it's wet in here!" to which another pup replies with, "Sorry." It is possible the pup who apologizes might be Whizzer.
Whizzer has also appeared in his own line of books, such as Whizzer's Bad Day and Whizzer's Christmas.
In Whizzer's Bad Day, it shows Whizzer trying to be optimistic and see the positive side of things that happen to him, such as him being splashed by the sprinkler is seen as a bath; when he accidentally trips and lands on his back, claiming that he saw a bone-shaped cloud when he did; when he also claims that he gets to decorate the road he is on; when he is covered in paint; and saying that he likes the sound of a bee that nearly stings him. He explains this to the Dalmatians when they ask him about it.
- In most tie-in material to the movie, he is portrayed as playful and loud, and often annoys his sister, Jewel.
- In some books, it is said that Whizzer likes to bark a lot and usually keeps the other pups up during the night with it.
- Out of all of the (named) supporting puppies in the TV series, Whizzer has the least amount of lines. With the exceptions of his speaking roles in "Love 'Em and Flea 'Em", "Bad to the Bone", "Walk on the Wild Side", and the Video CD version of "Dalmatian Vacation Part One: Road Warriors", most of his lines are only one word or cheering/laughing.
- In the episode "Purred It Through the Grapevine" (which is Whizzer's first speaking role in airing order), he is voiced by Pamela Adlon, the voice of Lucky, instead of Christine Cavanaugh.