Dirty Dawson is the Dalmatian pups' TV show villain and Thunderbolt's archenemy. During the screening, Patch constantly interrupts the other puppies by talking aloud, and even insults Dawson by calling him a yellow-livered old skunk at one point.
In the show, he is shown to be chasing Thunderbolt, with the horse thief shooting at him. The thief then travels on foot as Thunderbolt searches. In some scenes, it shows Thunderbolt making a leap across a canyon before it seems like Dawson has shot Thunderbolt. However, Thunderbolt is only pretending, and as Dawson laughs about this, Thunderbolt then attacks, and the two fall into a river, having the show end in a cliffhanger as the two are about to fall down a waterfall.
In the show, the dynamic and brave Thunderbolt and his offbeat sidekick Lil' Lightning fight to defeat the evil Dirty Dawson.
In an episode, Dirty Dawson kidnaps a helpless boy named Tommy. It is up to Thunderbolt and Lil' Lightning to defeat him before any harm befalls Tommy. As Dawson ties Tommy to a moving train, Thunderbolt perches on a cliff. He jumps to the train, confronting Dawson. Whilst Thunderbolt battles Dawson, Lil' Lightning unties Tommy. Dawson causes Thunderbolt to stumble between the train carts, and as he's about to strike Thunderbolt, another train heads by the train carts they are on, allowing Thunderbolt to get around Dawson. Thunderbolt then tangles Dawson in his own whip, tripping him up and causing him to fall into a boxcar with a mad bull that attacks him. Tommy is then rescued and Thunderbolt saves the day.
In a post-credits scene of Patch's London Adventure, Dawson notices Thunderbolt and Patch who try barking at him, before he gets chased by the Dalmatian pups.
In the film, Dirty Dawson is still an animated character, as he is shown as the villain Roger Dearly first intended for his video game, and who is later removed from it and replaced by an animated version of Cruella De Vil. Additionally, as the protagonists of the video game are animated counterparts of the Dalmatian puppies, it is also the only time Dawson directly interacts with the Dalmatians.
The One Hundred and One Dalmatians Diamond Edition Blu-ray features a Thunderbolt short based on early drafts of the scene, which follows the events directly from where they are seen in the animated 101 Dalmatians.
- The short shows that Thunderbolt and Dawson are able to catch branches sticking from the side of the waterfall. Dawson is able to reach a ledge and as Thunderbolt's branch is about to snap, his human, the sheriff, is able to use his lasso to save him. The two pursue Dawson, but the thief uses explosives to cause an avalanche, blocking their path and allowing him to take some sacks of money from a wagon, which may be why Thunderbolt is chasing him. The sheriff thinks Dawson has escaped, but Thunderbolt climbs across the rock pile to continue the chase.
- Dirty Dawson was an inspiration for Alameda Slim.