* 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.
* CrowningMomentOfHeartwarming: Thomas Edison, {{Jerkass}} and WellIntentionedExtremist though he may be, enjoying a quiet dinner with his wife in ''The Deadly Art of Science''.
** Also the reason why Edison started messing around with Odinic force in the first place [[spoiler: He was looking for a way the two of them could live together forever.]]
** From the same volume: every time Helen and Robo are together and Robo finally getting his own gun.
** Also: Robo brings Tesla soup. Soup carefully prepared so that Tesla can easily satisfy his compulsion to know the precise volume of his food before he eats it, letting him eat something other than crackers for once. Bonus points for being Robo's way of reconciling after the falling out mentioned below.
* EnsembleDarkhorse: Jenkins and Dr. Dinosaur.
* 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.