Dan is a human outlaw on Mars. He claims to be the best highwayman in history, and has a beloved knife, Stabby LaRoux.
In Cactoid Jim, King of the Martian Frontier - Space-coach, Dan attempts to rob the Space Coach which The Red Plains Rider and Cactoid Jim are guarding, with his knife, Stabby LaRoux. Red and Jim shoot Stabby, and the knife is ruined. Dan then Jetpacks away, and Cactoid Jim suggests he think about his loss and maybe it will turn him around.
In Hypercattle Overdrive, Dan has a new knife, Stabby LaRoux Deux, who is even deadlier and even more French. He holds up the hypercattle drive which Sparks Nevada and the Barkeep have been hired to guard. He stabs Sparks Nevada's guns to death, and then stabs the Barkeep, though not fatally. He is defeated when Pembroke Cartwright finds the hero inside of himself to punch Dan with Sparks Nevada's robot fists.
Later, in Mortified on Mars, Dan joins in on the singing "Riding the Galactic Trail" around the campfire. Sparks and the Cartwrights wake up the next morning to see that the hypercattle, Dan and the Barkeep are all missing. A note was left from NiceMan Dan apologizing, and admitting to stealing everything. When Sparks catches up with them, NiceMan Dan says that his well-planned scheme is a lesson to Highwayman Dan to show the benefits of planning ahead. Thanks to his father's plan, Highwayman and NiceMan Dan get away. It's unclear whether they were later caught or if they got away with the hypercattle, as they failed to kill Nevada and his friends but that was the end of the episode.
In Bonus Onus, Highwayman Dan attempts to put together a gang to raid a space train by taking out an ad in a local newspaper. Sparks and Croach attempt to stop Dan by joining the gang undercover, and then modifying the plan to have Dan and his accomplice instead get jobs at the topiary garden. When this plan is foiled by Felton, Sparks and Croach arrest Dan, instead.
- Cactoid Jim, King of the Martian Frontier - Space-coach (TAH #62)
- Hypercattle Overdrive (TAH #74)
- Mortified on Mars (TAH #78)
- Bonus Onus (TC #1)
Highwayman Dan is NOT the son outlaw in Father Reaches of Space. Confirmed with Acker & Blacker.