Action Girl: Pan. Her power level has to be higher than Android 20, as she was able to beat Android 20 easily, and was shown to be physically stronger than him. The only reason she seems weak is because Rilldo was stronger than Buu and the first Big Bad was in Vegeta's body, and had several power-ups, making him stronger than Rilldo. All the big bads after that were even stronger than them, making her seem a lot weaker than she would be against most everything in the galaxy.
Affably Evil: The Shadow Dragons are from created the negative energy that built up in the Dragon Balls every time a selfless wish was made, and the more selfless the wish was, the more evil the Shadow Dragon spawned by the wish is. note Syn Shenron, the most evil of the dragons, was created by the wish that resurrected everyone killed by Freeza on Namek, for example.Nuova Shenron was created by King Piccolo's wish for his youth to be restored, the most selfish wish made, so he's hardly a villainat all.
Afraid of Needles: Goku's fear of needles comes up for the first time since the Namek saga.
Chi-Chi: Wahhh I can't take it anymore! He turns into a child, he runs off on crazy adventures, and now he's got a ball on his head!
Artistic Age: An in-universe version is done with Goku's biological age. Goku's biological age is never stated, but Pan thinks he's gone to being 3 or 4. Others think he's about 10. Pan's age is officially 10, but due to this trope, nobody's completely sure, due to other sources giving different ages (but she's supposed to be 10). It is important to note that Goku is identical to how he looked age-wise in Dragon Ball (despite being a lot more muscular), so it is likely he is the same age as he was when he fought Pilaf.
Piccolo makes a brief appearance when Baby arrives on Earth, disappears after being blasted, and suddenly returns afterward only to die when Earth explodes to stop the Black Star Dragon Balls from ever being used again.
Krillin has this too, being killed by the Brainwashed and Crazy Android 17 after seeing only brief glimpses of him and 18 throughout the Baby saga. This being the series that it is, though, he gets better.
Nappa didn't have a chance against Vegeta after returning from Hell.
Back for the Finale: Almost every surviving character Goku, Pan, and Trunks encountered in space shows up and has a speaking part (or at least a grunt) in episode 63 where they help Goku take out the Big Bad. Goku Jr. and Puck from the TV special show up in the epilogue for episode 64. A video montage featuring all the characters from the past Dragon Ball series shows while Goku is walking through the tournament halls in the last minutes of GT in episode 64.
Badass Adorable: Pan. She may be a bit emotional, and can't really take pain at first, but no matter where you are in the show, she can kick ass. She just doesn't really get a chance to do it too often because the villains all need to be on Goku's level. Her lightning fast domination of Android 20 is a good example, however.
Badass: Most of Planet M-2, and things that come from there, like Luud.
Badass Boast: Goku gets one after his energy is restored to full near the end of his fight with Baby:
Goku: All you can see is the light shining through the cracks around the edges of the door, Baby. And you just don't think that little bit of light can overcome your dark plans. But what you can't see is what's behind the door. That's what I am.
Badass Family: While most of them are now retired from fighting, Goku's family still applies. Chi-Chi was a contestant in one of the World Tournaments, Videl may be the strongest pure human woman on Earth, Gohan could be the strongest anything on Earth if he applied himself, Goten could likely be just as strong as Gohan, Goku is the strongest non-fused character in the universe and is stronger than every single god in the universe, and even Pan has to be stronger than Android 20. Vegeta's family is pretty badass as well, seeing as Bulma was actually a badass at one point, Trunks has always been a badass, as has Vegeta.
Badass Grandpa: Though he doesn't look it (and after Pilaf makes that idiotic wish, he really doesn't look it), Goku.
Badass Moustache: Subverted with Vegeta. It's so bad that his own daughter scolds him for it and has it shaved off.
Bad Boss: Pan's ideas for getting the Capsule Corp. engineers to design new stuff is to cut their pay in half and take all their benefits. Because they said breaking the laws of physics was impossible, and they were wrong. Good thing she isn't in charge.
Balance Between Good and Evil: The premise of the Shadow Dragons saga. The good wishes our heroes made with the Dragon Balls over the course of the saga were displaced by an equal amount of negative energy, which was stored in the Balls. Thanks to the Dragon Radar being able to track the Balls so easily, new wishes were made far sooner than they were meant to. So rather than allowing the negative energy time to dissipate, it instead accumulated over time, eventually leading to the creation of the Shadow Dragons.
Bazaar of the Bizarre: The bazaar on Imecka sells everything from ammo (including huge bullets) to alien food and jewelry to living birds used as hats with red and white tail feathers and snakes for wearing around your neck.
Eis is German for ice. So "Eis Shenron" is literally "Ice Shenlong". The German version was likely used because of similar pronunciation, but with the right letter for the acronym.
The names of the evil Dragons are all based on the Dragon Ball they sprang from, which is written in Chinese in the original Japanese version. They're in the form of "_ Xīng Lóng" ("[#]-Star Dragon"), rather than "Shén Lóng" ("God Dragon").
Bittersweet Ending: Goku defeats the Dragons, then he has to leave with Shenlong to teach people to stop using the Dragon Balls for everything. The bittersweet part of this ending is that said mission will last for 100 years, and Goku will never see his family and friends again because, by the time he returns, they'll be dead by then. Except for Pan, her grandson, and the Androids.
Blood Knight: Goku and Vegeta. Pan takes it even farther than her grandfather at times.
Android 17 is brainwashed in this way as an essential part of the Super 17 arc. At one point he attempts to do this to 18 as well (and nearly succeds), and ultimate victory comes from our heroes reaching through his brainwashing for the briefest of seconds.
Bratty Teenage Daughter: Bra/Bulla, even though she's actually only about 10. She bitches at her father, Vegeta, until he shaves his mustache, and he almost kills a group of guys who hit on her, destroying their car and running them off the road, into the ocean. Plus, as a half Saiyan, she's easily strong enough to do her own bag carrying, and can fly, but won't.
Break the Cutie: Pan, after her parents try to kill her while possessed by Baby.
Brick Joke: The warning about abusing the Dragon Balls.
Butt Monkey: Trunks and Krillin. Vegeta has his moments too.
Can't Catch Up: Vegeta is pretty annoyed when he discovers Goku has left him in the dust again, with Super Saiyan 4. "The Heart of the Prince" really shows a look into his mind. Everyone else is pretty much pointless. Trunks is useful at first, but by the time Goku gets SSJ4, he's been left behind again. Pan is the only other character to stay important.
Combined Energy Attack: Played with by Baby Vegeta, gathering his followers' hatred of Goku in a massive energy attack appropriately named Revenge Death Ball. Played straight by Goku, killing Omega Shenron with a Spirit Bomb formed with energy from everyone in the universe.
Continuity Nod: Pan makes Trunks dress in drag so that he can defeat a monster demanding brides from a local village in order to obtain a Dragon Ball. Trunks' mother made Pan's grandfather do the exact same thing during their first Dragon Ball hunt.
Cool Starship: It has multiple rooms, a flatscreen TV, a game system and other things. Plus, it can break the laws of physics without being designed to do so.
Covers Always Lie: The season sets. SS4 Goku is on the first one, containing the first 34 episodes. He shows up in Episode 35.
Crapsack World: Just about every planet ever. The only ones to not be this had low-level civilization. Even the galaxy, and the universe, could be seen as this, with Hell opening up, a dimension that screws people over and kills them, and plenty more.
SSJ3 Goku gets this treatment by Baby Vegeta, and then proceeds to give it back when he becomes SSJ4.
Omega Shenron is the most powerful villain in all three entire series and he still gets this by SSJ4 Gogeta. Yeah he's that good.
Cute Bruiser: Pan, and possibly Goku again, depending on your definition of cute.
Cycle of Revenge: This started with the Saiyan-Tuffle War. The Saiyans wiped out their neighbors (without provocation). The last surviving Tuffles then created Baby, who would later take over Vegeta's body, as well as most of humanity, and all the people with Saiyan blood on Earth besides for Goku and Pan. Because of this, Goku is forced to kill Baby. This potential plot is never pointed out in the show and the feud apparently ends when Goku kills Baby.
Dark Is Not Evil: Super Saiyan 4 Goku. Longer, even blacker hair, a deadly serious voice and personality, covered in dark red fur, dark red eyeliner, and downright frightening to be against. However, it's still Goku.
Pilaf shows up, but ceases to be important after the first episode. His wish causes the dragon balls to be flung all over the universe, where the "apparent" real Big Bad Dr. Myu and his minions start collecting them. However, he's eventually killed by Baby, who takes on the role (until he is in-turn killed by Goku). While in Hell, Myu joins forces with Gero and creates Super Android 17 seeming to reclaim his status as main villain... but then 17 kills both him and Gero. 17 kills a lot of people before being taken down. This forces Goku and company to use the Dragon Balls to try and undo the damage. Unfortunately, the overused balls summon the One-Star Dragon ("Syn Shenron") and the shadow dragons. In other words, with the exception of One-Star, every one of these villains was a Disc One Final Boss.
General Rilldo was definitely one of these as well, and a disappointing one at that. At first, he's introduced as more powerful than Majin Buu (the strongest villain in DBZ), has multiple forms and actually defeats and imprisons all three of the heroes at first. But then gets killed disappointingly easily two episodes later.
Dub-Induced Plot Hole: Quite a few in Funimation's dub, but the most egregarious example is Goku wondering whether he would have to go back to school after being turned into a child. Only he was raised in the mountains, lived in complete solitude and never even met another person besides his grandfather until he was 12, and he never went to school (Muten Roshi's training, which included some studying, doesn't count).
Dub Name Change: This happened to the Shadow Dragons; in Japan they were simply referred to by their Chinese number (as in, "Six-Star Dragon") like the Dragon Balls themselves, while the American dub gave them descriptive names. The Canadian Blue Water dub kept the original names.
Eat Me: Uub allowing Baby to eat him, which allowed him to launch a surprise attack from inside Baby's stomach.
Earth-Shattering Kaboom: The side-effects of the Black Star Dragon Balls. You use them, and you get one year to retrieve them. Otherwise, boom. The first time they get used, they are retrieved. The second time, everyone is too busy stopping Baby after he uses them. The Earth explodes, but not before everyone who isn't Piccolo is saved. Then they wish Earth back.
Enemy Mine: The fight with Luud ultimately boils down to this.
Establishing Character Moment: Pan gets one that lasts from her first appearing to them going to space. First, her breaking up the bank robbery, and then her being treated like (and complaining about being treated like) a kid (she's 10, so it does make sense). Then, her stowing away and basically stealing the ship when Goku and Trunks discover her. Trunks gets one in the form of him abandoning Capsule Corp and flying off, changing in the clouds.
Everything's Worse with Bees: Averted. The giant bees are pretty much harmless, though they do mistake Pan for their queen. The baby bees are the cutest things ever, though.
Evil Is Deathly Cold: Played straight with the Three-Star and Four-Star Dragons. Three-Star has powers over ice, and Four-Star has powers over fire. Three-Star is bad, Four-Star is good. They're twin brothers, by the way.
Evil Knockoff: Dr. Gero and Dr. Myu create a new Android 17 in Hell and somehow use him to open a portal to Earth.
Evil Sounds Deep: Played with. Baby is high-pitched, but some of the Shadow Dragons are extremely deep.
Evolving Credits: About halfway through the series, the opening credits, which originally ended with Goku, Pan, and Trunks beating up some mechanical giant, now ended with the three of them fighting Baby, even after the Baby arc ended.
Franchise Zombie: Z already had signs of this, but Toriyama no longer had any hand in the story outside of a basic outline.
Freeze-Frame Bonus: At one point, Chichi slaps Baby-possessed Goten so hard that he goes careening past a shelf and knocks over two pictures. One of them is a generic picture of Bulma, Vegeta, and their kids, but the other is of tiny, DBZ-aged Bra being held by Vegeta and pulling his face into a really annoyed smile.
Gainax Ending: Clear proof that GT was a very rushed concept. What happens to Goku in the last 2 episodes is inexplicable and there's no official explanation. He's finished, then he's dead and he talks to the world, then suddenly he's alive again, then in base form he cannot be killed by Omega (there's not even a halo to give us any idea), then after the bomb's thrown, he's apparently dead again and brought back to life, then he leaves. Vegeta knows something's up, then suddenly we see Goku's clothes left on the ground (that shot is chronologically out of sequence and is shown at the end of the next couple of events). DBZ's version of No Body Left Behind doesn't leave clothes behind. But then he's off to visit Roshi and Piccolo still fully clothed, and both also know something's changed about him, but "Are you...?" is not very helpful. When they take their eyes off him for a second, there's suddenly no one there, which is almost creepy. Then for some reason the Dragon Balls merge into Goku, then he disappears. Where does he go? What happened to him? He doesn't return for 100 years, and, if you leave aside what you saw in A Hero's legacy, it's not clear if he's alive or dead (and, if he's alive, why he's only aged about 30-40 years instead of the full 100). To top it all off, he doesn't even seem bothered by the fact that almost everyone he knew is dead. It doesn't add up to his fate in A Hero's Legacy. Goku is clearly no more and it makes it appear like the whole cast just passed on when their time was up. However, A Hero's legacy was made earlier just after the Baby Saga and they intended Goku to be clearly dead by this point and be the Spirit Advisor to Goku Jr. At that time, no one had any idea how GT was going to end or just how they were going to get there. Seriously.
Half-Human Hybrid: And how! Bra, Trunks, Gohan and Goten. Pan is a 3/4ths human, and Goku Jr. is either 1/16 or maybe more Saiyan that that (you know, on the off chance the Pan/Trunks shippers are right).
Happy Flashback: Used to get Goku under control when he was giant, golden ape.
Heroic Sacrifice: Piccolo (twice, once after he's dead), Buu, 18 tries, possibly Earth Android 17, and others. The Four-Star Dragon dies to save Goku.
Hell on Earth: The Legions of Hell return in the Super 17 arc. Also, Cell and Frieza have their own trap for Goku turned against them in Hell.
He Who Fights Monsters: The Tuffles. They were a peaceful people (according to Baby and King Kai), who were almost completely wiped out by the Saiyans (who may or may not have been previously enslaved). So they created Baby, who plans on turning the entire galaxy into Tuffles. Nice, you went from genocidees to genociders.
Kid-Appeal Character: Pan is a Type 3. Even if she'd get destroyed in the main fight, she still tends to try, and if she's not doing that, there's a good chance she's doing something else on her own, which tends to help out (pursuing Giru, finding and saving the kid who was possessed by Baby, and calming Goku down while he was a Golden Great Ape are all good examples).
Killed Off for Real: Piccolo stays behind on the exploding Earth so that the Black Star Dragon Balls cannot be used again. He cannot be revived without the Black Star Dragon Balls coming back, so he stays dead.
Little Stowaway: Pan. The reason they don't take her home is because she takes the device that would let them go home and easily keeps it a away from the out of practice, not to mention larger, Trunks. Goku refuses to interfere with it, and she finally drops it down her shirt (which, when you think about it, shouldn't work), causing Trunks to give up.
Living Prop: Bra does about three things in GT. Get Vegeta to shave that awful facial hair, make Vegeta take her shopping, and give some power to Baby. About the only reason they included her seems to be to give her something to do, since Toriyama introduced her in the next-to-last chapter of the manga.
Misplaced Retribution: Baby's attack on Goku, Trunks, Pan, Vegeta and the other people with Saiyan blood, as well as all of humanity, and he plans to attack the entire galaxy. This is all revenge for what the Saiyans did to the Tuffles. Vegeta and Goku were not even born yet (and Vegeta would have been a baby if he was), the others were certainly not born yet, the rest of the galaxy wasn't involved, and Frieza killed all the Saiyans who could have been there in a combat role (as in, not babies). Basically, he's taking out his anger over what King Vegeta and Bardock's generation did on their kids, grandkids, great grandkids, friends, family members, fellow inhabitants of the Earth and fellow inhabitants of the universe. Both Goku and Pan flat out tell this to Baby. He doesn't care.
The Mole: After arriving on Planet M2, it's revealed that Giru was working for the bad guys all along. Except it turns out he wasn't and that he was working for the good guys, by deceiving Rilldo and the Machine Mutants. So he was actually a Reverse Mole.
Monster of the Week: In an interesting display of symmetry, the show used this format in the Black Star Saga (the first arc) and the Shadow Dragon Saga (the final arc).
Mood Whiplash: Often caused by trying to accommodate both early Dragon Ball's comedic tone and the more serious action of Z. The worst offender is by far the Shadow Dragon Saga.
Nice Hat: Pan's fisherman's hat in episode 64 and A Hero's Legacy.
Never Forgotten Skill: Played with quite oddly. After being turned back into a kid, Goku is unable to use his Instant Transmission technique and Trunks theorizes that since Goku is a kid again, he can't use any technique he learned when he was an adult. However, Goku pulls off the techniques of flying, turning Super Saiyan, and sensing energy with little difficulty...despite the fact that he never learned them back when he was a kid.
Never My Fault: Bulma manages to blame Goku for starting the cycle of searching for the Dragon Balls, when he didn't even know what they did until he met her.
Nice Job Breaking It, Hero: The constant overuse of the Dragon Balls over the course of Dragon Ball and Dragon Ball Z is what causes the creation of the Shadow Dragons.
Nice Job Fixing It, Villain: Baby does this, having used the Black Star Dragon Balls to bring back Planet Plant. Because of this, and the year long (well, just about) reign afterwards, by the time he's dead, Earth has two weeks left. Luckily, there's still a planet just sitting there, as well as a giant spacecraft and Super Saiyan 4 Goku, who can use instant transmission. So, had Baby used that wish for something like immortality or even just Planet Plant in it's old place, Earth would have been screwed.
No Endor Holocaust: Earth is so lucky this universe ignores physics. For one thing, it would be bombarded with the remnants of... itself, from the last two times it exploded. For another thing, if a planet were as close as the restored Planet Plant in real life, the gravity of the two would first pull them to the point where they'd be slightly elongated. Second, their gravity would pull them towards each other. The two would then collide, doing massive damage to both. A very popular theory these days is that Earth used to be a Superearth, a giant Earthlike planet almost completely covered in oceans. Then it hit a Earth-sized planet. The chunks left over from the two gave us the moon, and the Earth became what it is today (after millions of years of pulling itself together).
No Guy Wants an Amazon: Pan's date in the first episode. He's not exactly a fan of her kicking the asses of a group of bank robbers and saving (what she thinks is a) small child.
No One Should Survive That: At one point, Pan, Goku and Trunks get so close to a sun that, by all scientific information available, their ship should have melted and they should have instantly been burnt to a crisp.
No Saving Throw: Earth Android 17 vs. Hell Fighter 17, when Earth 17 attacks Krillin and 18.
Oddly Common Rarity: In Dragon Ball Z, the need for a spaceship was something really, really bad. Not even Capsule Corp could pull that off. Now, Capsule Corp can build spacecraft within the week, complete with extras like a flatscreen TV.And that's when it takes off before it's even ready.
Off Model: Nearly the entire series. When it comes to Z, there were quite a lot of off-model moments, but when it came to scenes directly off manga material, you could see the difference. GT's art seems to be a case of Toei being lazy; it barely resembles the sharp, angled art style Toriyama employed by the end of the manga.
Goku. It's apparently a Saiyan trait. Even before turning into a kid, he's supposedly in his 40s-50s, and yet barely looks any older than in the Cell saga of Z. Immediately after being reverted to child size, he makes a reference to Compulsory School Age in the Funimation dub.
Vegeta, for the same reason (as he's the only other full-blooded Saiyan left). He's 5 years older than Goku, meaning he's mid to late 50s by now.
Despite looking like a little kid, Pan might actually be somewhere in her early teens. It depends on how long you think the Time Skip between Z and GT is (according to the original Japanese, it's 5 years after the end of DBZ, which was 10 years after the Buu Saga).
Power Limiter: Goku's power drops along with his size. Not to the same level he was at when he was actually a kid, but he he loses key abilities like the Super Saiyan transformations and Instant Transmission.
Punny Name: Don Kee (it makes more sense in Japanese, where he's "Don Kia", a pun on akindo, meaning "merchant").
Put on a Bus to Hell: Piccolo, quite literally. After he's already dead. But on the other hand he went himself there on purpose, actually prefers being there and uses his newfound position to guard Hell as seen at the end.
Real Song Theme Tune: In marked contrast to earlier series, GT used random pop songs from popular Japanese artists of The Nineties, including the late Izumi Sakai (a.k.a. ZARD), idol Shizuka Kudou, and pop staples DEEN, WANDS, and Field of View. They're fairly memorable, but they really have absolutely nothing to do with the series in terms of lyrical content.
Recycled Premise: The Tuffle Arc is recycled almost entirely from Plan to Eradicate the Saiyans. Baby is a rather obvious expy of Hatchiyack being a tuffle creation who seeks to avenge his race by any means necessary.
Shoot the Hostage: in an attempt to stop Super 17's rampage, Pan and Giru manage to block Dr. Gero and threaten him with death. Sadly, because Dr. Myuu secretly modified Hell Fighter 17 in order to make him respond to his and his only orders, Super 17 doesn't recognize Gero as his boss anymore. Which leads to Gero's nth death at the hand of one of his creations.
The Planet Gelbo features a native species of pointy eared humanoids. Its original name, Kerubo is an anagram of "Borukeno", which is a Japanese spelling of the word Vulcan/Vulcano.
Significant Acrostic: The American names for the Shadow Dragons start with the letters S-H-E-N-R-O-N. Specifically note that the letters are in Dragon Ball order too (for example The 1 star dragon being "Syn Shenron" and the 7 star dragon being "Naturon Shenron").
Sins of Our Fathers: Baby is out for revenge against the Saiyans, of whom Goku and Vegeta are the only full blooded survivors. And he willingly states this word by word when he's telling Vegeta his backstory.
Sissy Villain: Lord Don Key of Imecka, and Master Doltaki the "Oracle" of Lord Luud.
Soundtrack Dissonance: Quite a few of the songs used in DBGT's soundtrack, including the OP and Ending songs, are pretty blatantly romantic in nature. While Goku and Pan do love each other very much, its probably not even remotely in that way, and it doesn't really fit any part of the series at that. They are still very good songs, nonetheless.
Space Brasilia: The ruins of the city seen on M-2 are clearly this, just with a long period of abandonment after the apocalypse.
Super Mode: While Z only went to level 3 of the transformation, GT in particular is notable for introducing Super Saiyan 4, which is so powerful that a Saiyan must become a Golden Great Ape before attaining this form, and unlike all others, this form involves a Saiyan keeping their hair dark but having a copious amount of it as well as growing red fur all over their body and regrowing their Saiyan tail if it's missing.
Superpowered Evil Side: SS4 Goku, and Golden Great Ape Goku. GGA is just plain destructive, but SS4, at least the first time it's used, is like the first time Goku went Super Saiyan, only even more serious.
In both English dubs, Goku's actor changes as he shifts between his child and adult/SSJ4 bodies.
In the Funimation dub, Pan's actress changes during the flashbacks from when she was a toddler. Oddly, this is averted with old lady Pan, who has the same VA as 10-year-old Pan.
Time to Unlock More True Potential: The Kais think Goku's in for this after his first defeat by Baby Vegeta. Played with in a sense, as all Goku needs to unlock his potential is to have his tail grow, in a particularly painful manner involving a pair of pliers.
Vague Age: Pretty much everyone since it's never entirely established how many years have passed between Z and GT (the GT Perfect File companion books give it as 5 years, but certain dates appear to be reckoned assuming a decade since the end of Z). For example, fan sites have placed Pan anywhere from 10 to 14.
Villain Forgot to Level Grind: Painfully apparent when the old villains escape from Hell. Vegeta defeats Nappa without even trying, and Goku beats Freeza and Cell effortlessly in spite of the trap they set for him.
Wax On, Wax Off: Old Kai has Goku unlock his hidden power by making him operate a giant coffee grinder. Somewhat subverted as the actual goal was simply to regrow Goku's tail, and the training is quickly abandoned for the faster solution of simply forcing the tail out with a pair of pliers.
Wham Episode: "The Greatest Surprise" and "The Shadow Dragons".
What Happened to the Mouse?: What happened to Planet Plant/Vegeta? Is it just following Earth around? Did they blow it up? Seriously, there's a planet right next to Earth, in Earth's orbit. What happened to it? What ever became of the killer robots in possession of an industrial complex encompassing the entirety of Planet M-2?
What Measure Is a Mook?: Giru is treated like a full character, having started out as a good guy. However, he's still a Machine Mutant. The rest of the Machine Mutants are killed without any moral problems, despite the fact that the are clearly sentient.
What Measure Is a Non-Human?: The Machine Mutants are treated like your standard mooks. That is to say, slaughtered. Fridge Horror sets in when you remember that they're all sentient, and at least some, like Rilldo, have souls. This is also evoked when Giru first joins the team. Pan starts threatening Giru after he assimilated their Dragon Radar, when Trunks stops her. She tries to say he's Just a Machine, but Trunks explains that because the little robot is clearly experiencing fear, it must be sentient, and should be treated as such.
With Great Power Comes Great Insanity: Baby Vegeta worries he'll become this in exchange for the power to match SSJ4 Goku, and it is subverted when he reveals he still can talk and reason... but not for long, as he slowly but surely begins to lose his grip on sanity, as a result of both his unnaturally enhanced power and his maniacal obssession to kill Goku at the expense of everything else, even his own planet.
You Can Keep Him: In the first episode, a group of criminals tie up Goku, and call Caspule Corp, hoping to ransom him. Vegeta answers, listens to their demands, then nonchalantly states "You can keep him."
Failure Is the Only Option: From the get-go, anyone remotely familiar with the show knows that Goku Jr. isn't going to get the resolution he wants in his quest (not directly, anyway), because he has no idea how the Dragon Balls work and just assumes one will do the trick. The original Goku even points it out at the end, and is surprised Pan never explained how they work. Of course, thematically, getting the Dragon Ball was never really the point.
Identical Grandson: Goku Jr. Technically, he's Goku's Great Great Great Great Grandson (according to the final episode of GT, anyway; he just calls Pan "grandma" in the special). However, while looking exactly like Goku, he has a completely different personality.