* CrazyAwesome: Dr. Dinosaur. He's an insane, MadScientist dinosaur - resembling a species from Film/JurassicPark more closely than anything that actually existed - who claims to have traveled through time and space to destroy humanity and make dinosaurs rule the Earth once more. He's also appears to be invincible having survived shootouts and fistfights with Robo, getting smacked full-tilt by an armored truck, and being close to a bunch of grenades exploding and taking out Robo. He spends his time doing things like shooting up 4th grade science fairs to steal a little girl's experiment, buying guns by using a children's picture book as ID, and trying to kill Atomic Robo for little to no reason.
* CrossesTheLineTwice: Half the stuff Dr. Dinosaur does.
* EnsembleDarkhorse: Jenkins, even though he is ''technically'' the main character's sidekick, is an unstoppable OneManArmy with hilariously overblown results and comically feminine interests. Dr. Dinosaur is a hilarious one-off villain created for a free comic book day story who quickly became one of the hero's main antagonists.
* EvilIsCool: Baron Helsingard and Edison.
%%* {{HSQ}}: Volume 8's ending.
* HilariousInHindsight: Doctor Dinosaur has teeth that portrude from his mouth. A later study showed that ''real'' Utahraptors have that too.
* JerkassWoobie: Thomas Edison.
* MemeticBadass: Jenkins. Even '''the writer''' thinks he's cooler than the main protagonist. The TabletopGame adaptation making him more expensive to play than the bulletproof, superstrong industrialist-adventurer he works for doesn't help.
* {{Tearjerker}}: Robo and Tesla's falling out in "The Deadly Art Of Science".
** TheReveal that [[spoiler: Edison became evil because he wanted to be with his wife forever.]]
* TheWoobie: Robo himself.