You wouldn't think a lighthearted show about a butt-kicking battle robot could be scary? You'd be wrong.
- With it being an episode revolving around nightmares, "Kamikazi Nightmare" has its fair share of scary imagery, such as characters getting covered in insects, Kamikazi's various hallucinations upon eating the tainted tapas, the climax where the ray gun malfunctions and causes the environment to transform into a cave populated by giant hostile insects, said insects bleeding, and the ending where after eating the tainted tapas, Gus has a red slug grow out of his ear, he eats it, and then is shown to have had his lower half turned into a slug's foot. All while being oblivious to it all.
- Protoboy in general. Anyone familiar with how comedic the show's villains tend to be will be in for a surprise when this guy shows up. As shown in "Brother", he was Moshimo's first prototype robot, who was devoid of Robotboy's humanity and was quite vicious towards the professor. He was later kidnapped by Kamikazi and reprogrammed, too well infact, causing him to become too evil for him to control (and perhaps too evil for the show). He is taken surprisingly seriously, especially after he makes his return, where he's a full-on Knight of Cerebus. To put it straight, he is one, if not the only villain to attempt mass murder.
- His garbled, somewhat high-pitched, electronic voice is also pretty unnerving. His more audible, deeper and more monotonic voice in his later appearances isn't better by much, especially when he says something disturbing and/or sadistic.
- Kamikazi successfully reprogramming Robotboy in "The Tune Up". There is just something eerie seeing Robotboy with a completely blank look on his face, devoid of any emotion.
- Even worse is Kamikazi ordering him to kill Tommy, all while cracking jokes and remarks. Even Constantine is unnerved by Kamikazi's sadism.
- How Evil 17 became an exact imposter of Tommy in "Double Tommy". It isn’t shown, only mentioned, but it is stated that Kamikazi had surgery preformed on him without his permission. He warms up to it, but still, it's an unnerving idea to think about.
- "The Revenge of Protoboy" is arguably the darkest episode of the series, while easily being the most intense, with several different scenes that head straight into What Do You Mean, It's for Kids? territory.
- Protoboy violently beating Robotboy up at the start. He shoots him with his arm cannon, punches his ears off to the point they are just hanging on by wires, rips him in half with his Eye Beams before kicking him and violently grabbing his face in a painful looking way, and throwing him at the wall of Tommy's house. He would have killed him right there if he didn’t get a phone call from his "Dear".
- Protoboy grabbing Tommy with the implication he was strangling him using his shirt. Not even Kamikazi would go that far (maybe). This is practically seen as the moment Proto crossed the Moral Event Horizon in-universe.
- Right as he attempts to destroy the ship, Protoboy has his already unnerving face framed-in shadow except for his glowing red eyes, which only serves to make him look terrifying. This is not helped by his remark about wishing Robotboy could see him destroy it and kill everyone on it.
- Protoboy's death. Robotboy lunges at him, punches a hole in his chest and violently tears out his motherboard on-screen (made worse by how the burst of electronic sparks when Protoboy's motherboard is torn out kind of resembles a blood spray), causing him to revert into his deactive mode shortly after. We even get a good shot of the hole in his chest. This is made worse by how, despite the lighthearted tone the series usually takes, it's all played dead seriously.
- The simple fact that Robotboy, deliberately KILLED someone, his own brother, in a manner akin to something out of Mortal Kombat. Protoboy does get better, and its the norm for him, but it doesn't migrate the nature of the scene. It should say something that Robotboy did something like that.
- Robotboy himself's cold attitude in this scene might also come off as chilling. The look of disgust and hatred he shows as he appears from behind Protoboy, how he violently lunges at and mutilates him while screaming "hi-yah!", and the cold Death Glare he has when he finally dies. It seems to serve as an indication that he has had enough of trying to redeem him, and he despises him as much as anyone else. The sad face at the end almost seems jarring from how he was before.
- Protoboy's last words here, "it can't be", could simply just mean that he doesn't believe that Robotboy is alive or him denying his defeat. But you could also interpt it as an implication that even he of all people is shocked by what Robotboy just did.
- Think about it from Protoboy's perspective. You just thought you had killed your archenemy, and were ready to finish off what he tried to save, only for you to hear him behind you, you turn around and see him completely unharmed and absolutely pissed, much to your surprise or even horror. And before you can even get the chance to comprehend how he's still alive, he lunges at you and tears your circuits out. You look at the hole in your chest before gazing into his cold, unfeeling glare, once more in denial of how he's alive, before you are no more.
- Some of the violence can be rather disturbing, even though they usually aren’t graphic and mostly happen to non-humans, they include being crushed to death, shot to death, exploding, getting strangled, being Eaten Alive, getting electrocuted, motherboards getting ripped out, getting torn in half, melting, and being torn apart.
- The premise of "The Old Switcharobot" is very much Paranoia Fuel, where Protoboy steals Robotboy's body and pretends to be him.
- While not as graphic as "The Revenge of Protoboy", seeing him in Robotboy's body getting reduced to a pair of charred legs by Brainy Yak is disturbing. Especially when you consider that this is onscreen murder.
- The transmission in "The Return of Robotgirl" is rather unnerving, a desperate Moshimo in "great danger", is telling Robotgirl to quickly leave and tell Tommy he's in danger, saying "he'll get us any second". The transmission cuts off before we can find out who exactly was after them, or what happened to Moshimo.
- When Robotboy and his friends finally arive at Moshimo's current whereabouts, it turns out to be a desolate and abandoned titanium factory which Robotboy even lampshades as being "creepy". They then find Moshimo in a titanium mold, warning them to get out of the place and how "it's a TRAP!", revealing the whole thing to be a set-up by none other than Protoboy.
- The way Protoboy was going to kill his siblings and creator is pretty horrific, he was going to pour molten titanium on them, which would then shortly afterwards freeze solid, basically making a gruesome statue of their remains.
- Protoboy kicking out Robotgirl's batteries and attempting to kill her, with the implications she's in a And I Must Scream state during it all.
- The fact that Protoboy actually surivives at the end, unlike every other episode he appears, which ended with him getting killed.
- A more subtle example is Donnie Turnbull's behavior, namely the fact that he tries to murder his own brother by tossing him into a woodchipper, which would have lead to the great grandmother of all gorey demises for poor Tommy, but his disturbing behavior doesn't end there, as in the episode Underwater, he outright says the main reason he's excited for the fishing trip is that he'll get to cut open and gut fishes. Suddenly, Donnie seems less like a bully and more like a budding sociopath, given he displays no restraint whatsoever in trying to murder his brother and is giddy about harming animals.
