TV-Series
Description
Dr. Gero, the brilliant but vindictive scientist formerly of the Red Ribbon Army, plays a crucial role in the Super 17 saga of Dragon Ball GT. Having previously transformed himself into the android known as Android 20, his story in GT begins after his death. He is depicted in Hell, where he forges an alliance with the evil scientist Dr. Myuu, the creator of Baby. Together, they collaborate to create a powerful new warrior, Hell Fighter 17, a replica of Android 17 designed to be a weapon of pure destruction. Their shared motivation is a deep-seated grudge against the Z-Fighters, particularly Goku, and a desire for revenge. The two scientists succeed in opening a rift between Hell and Earth, unleashing chaos and allowing Hell Fighter 17 to fuse with the original Android 17 on Earth to become the unstoppable Super 17. Dr. Gero's role is that of the master planner, driven by his lifelong obsession with defeating Goku and proving the superiority of his artificial creations. However, his partnership with Dr. Myuu is built on distrust. After Super 17 is created, Myuu alters the android's programming to be loyal solely to him, betraying Gero. When Gero confronts his former partner, Super 17 turns on and kills his creator, showing that even in death, Gero's ambitions lead to his own destruction at the hands of his own flawed creations. His key relationships in GT are exclusively with Dr. Myuu and Super 17, with the latter being the ultimate culmination of his life's work that ultimately rejects him. Dr. Gero's development in GT is minimal, as he remains a static character defined by his intellect, arrogance, and petty vengeance. His notable abilities as an android include flight, energy absorption through his palms, eye beams, and superhuman strength, though in GT his primary function is as a strategist rather than a direct combatant.

Li Shenron, also known as the Two-Star Dragon or the Haze Dragon, is one of the seven Evil Dragons born from the negative energy accumulated within the Dragon Balls after decades of overuse. His character is unique among the Dragons as he embodies the concept of pollution and toxicity rather than raw physical might. Possessing a small, turquoise, childlike body, Li Shenron is easily underestimated, but his arrogance and deceptive nature make him a serious threat. His motivation is primal and simplistic, driven by a desire to spread his pollution and eliminate those who would oppose the Evil Dragons. In the story, he is first encountered by Goku and Pan when he attacks a village near a lake. His primary ability is not brute force but the generation of a corrosive, poisonous mist and the contamination of water sources with his negative energy. This toxic haze saps the strength and energy of anyone exposed to it, effectively neutralizing more powerful opponents like Goku. A notable aspect of his background is that he was born from the pure-hearted wish that resurrected Bora, the father of Upa, in the original Dragon Ball series, a stark irony that shows even good intentions can have dark consequences. Li Shenron is among the first of the Evil Dragons to be confronted, and his role is to demonstrate that these new enemies cannot be defeated by power alone; they require cleverness and environmental awareness to overcome. Goku and Pan are initially unable to land a decisive blow as the poison weakens them, and the only way to defeat him is to find a source of pure spring water to wash away his contamination. Li Shenron has no significant relationships with other characters beyond being a subordinate to his more powerful brother, Syn Shenron. His development is non-existent, as he is a single-episode antagonist. Beyond his mist generation and the ability to inflate his body to deflect physical attacks, he possesses no other notable abilities and is ultimately destroyed by a combined Kamehameha from Goku and Pan.

Nappa, the towering and brutish Saiyan warrior, appears only briefly in Dragon Ball GT, serving as a cameo antagonist during the Super 17 saga. His role in the story is minor, existing primarily as a callback to the Dragon Ball Z era. Along with other villains, Nappa escapes from Hell when the barrier between worlds is broken by Drs. Gero and Myuu. He reappears on Earth and immediately resumes his destructive ways, causing chaos in a city. His personality remains entirely unchanged from his original appearance; he is still loud, arrogant, crude, and relishes the opportunity to cause massive destruction, as shown when he uses his signature technique to level a city street. His surface-level motivation is to wreak havoc and presumably get revenge on the Z-Fighters who defeated him years ago. The key relationship he has in GT is with his former comrade, Prince Vegeta. When Vegeta confronts him, Nappa charges at his old commander with a mix of rage and a desire to prove himself, but the encounter is incredibly brief. Vegeta shows no hesitation, immediately dismissing Nappa as a fool and an embarrassment to the Saiyan race before obliterating him with a single, effortless energy blast. This scene serves less as a meaningful fight and more as a demonstration of how vastly more powerful Vegeta has become, emphasizing that a once-terrifying enemy is now nothing more than a minor inconvenience. There is no character development for Nappa in GT; he is a static relic of the past brought back for a moment of fan service and to be quickly disposed of. His notable abilities, such as the explosive wave attack and his immense physical strength, are on full display, but they prove entirely useless against the modern level of Saiyan power.