Co Dragons: As the evil Green Ranger. Goldar hates him, but Scorpina doesn't seem to care.
Curb-Stomp Battle: As the evil Green Ranger. After that, they had him doing his own thing for a while, but coming whenever the other Rangers summoned him (this had to be done to keep him in time with Burai). Then came "The Green Candle", where he was curbstomped himself.
He then does this to Goldar in Season Two unmorphed after Lord Zedd drained the last of his powers. After this, Goldar was never the same again.
Darker and Edgier: Easily the darkest story of the original Rangers.
Discard and Draw: Happened to everyone, but associated with him more than anyone.
Incest Is Relative: Implied twice. Once in the Stable Time Loop, and once in the episode "Wild West Rangers", wherein it's implied he and Kimberly are both descended from Kimberly's ancestor and the White Stranger. And this is a kids' show?
The Hero: Got promoted to this trope when Jason left with Zack and Trini for the Peace Conference.
Stable Time Loop: Fan theory is that Tommy's clone Tom is also his ancestor. Which just adds one more bit of Memetic Badass: Tommy willed himself into existence.
Super Soldiers: What the other Rangers suspect the White Ranger is at first.
Verbal Tic (His distinctive "sikKEYAHHH!" when fighting.)
What Could Have Been: Jonathan Tzachor a producer on the show and big fan of Sentai wanted Tommy to die just like his sentai counterpart, but he was overruled presumably for BS&P reasons. Seeing how Tommy's popularity was a huge contributing factor to Power Rangers becoming popular enough to exceed its original order of 40 episodes, this was probably a good thing.
In earlier scripts, Tommy was going to be a biker named Rocky.
Zack Taylor / Black Ranger I | (Actor: Walter Emanuel Jones)
The Gun Slinger: He could wield the axe in close combat, or he could flip it around and use it as a laser gun. The blade served as the trigger and the handle became the barrel.
Brainwashed and Crazy: Averted in a Crowning Moment of Funny. Goldar kidnaps Kim and gives her a mind control spell which will turn her into a copy of Rita for Zedd to marry. The spell doesn't actually work... but Kim does a pitch-perfect Rita impersonation (including "I'm having a headache!") to hold Goldar, Squatt and Baboo off long enough to be rescued by Billy and Trini.
The Chick: Not only that but she was the template for all Power Ranger chicks thereafter (minus the valspeak).
Ill Girl: Without her power token, she becomes weaker.
Rule 34: Granted, many of the Rangers could qualify for various reasons (Trini for She's a Man in Japan, the male Rangers for being Mr. Fanservice or Chick Magnets, all the brainwashing), but Kimberly had a whole newsgroup dedicated to her. And like Austin St. John, Amy Jo Johnson was rumored to have starred in porn.
Valley Girl: Early on. Barely used any valspeak by season 3, as the whole concept was a more than a bit dated by 1995, the height of the grunge era.
Billy Cranston / Blue Ranger | (Actor: David Yost)
All There in the Manual: Billy's last name was actually never said during the series, but was provided via related merchandise and confirmed by Word Of God.
Blade on a Stick: The Power Lance is essentially a two-sided trident.
Dual Wielding: Billy could use the Power Lance as a Double Weapon, or he could separate it into two shorter tridents and wield one in each hand.
Genius Bruiser: Starts off as a Straight A nerd but then becomes a power ranger.
The Glasses Come Off: Starts slowly during the helmetless scenes beginning in "The Mutiny". He officially lost them after the movie (during season 2) and when he returned to the show, they explained he replaced them for contact lenses. He would wear them two more times in Power Rangers Zeo.
David Yost: the glasses came off actually when we went to shoot the movie in Australia and that's because I told [laughs], I told the (movie) producer, this is without the creators or producers of the TV show knowing, I told the producers of the movie that I would rather not wear my glasses and they were like, okay [laughs] like they didn't really think anything about it.
He also stated in the same interview that because the glasses weren't real, they began to affect his vision (they had no prescription, but the chemical they used to prevent glare affected them enough to bother him.)
Hollywood Nerd: They tried to dress him to conceal that he's muscled like a plow horse. Didn't work.
They didn't even bother hiding his huge muscles in The Movie; then again, the movie never portrays him as the Smart Guy or a nerd.
Law of Chromatic Superiority: Not only does he get to use the Dragon Shield (the so-called "first Battlizer") until Tommy gets back, but he also gets the first self-transformable Zord.
Super Mode: As mentioned above, he at one point gained the power to use the Green Ranger's powers in the form of the gold Dragon Shield and the Dragon Dagger.
Secret Keeper: With Rocky and Adam from "The Ninja Encounter" to "The Power Transfer".
She's a Man in Japan: She is Trini's successor, plus the fact the her mechas are used by male Yellow rangers in Japan.
Note by the time Aisha became the Yellow Ranger, they were no longer using Zyuranger footage and all the scenes with the Rangers were American footage, thus preventing this.
Actually, they still reused Stock Footage, most especially the Thunderzord summoning sequence, but it was indeed to a much lesser degree than Trini.
Expy: Even though there was no robotic sidekick in Kyoryu Sentai Zyuranger, there were similar characters in previous Sentai seasons. Namely Peebo, Mag, Colon, and Arthur G6. Of course, there was a sidekick in Zyuranger, but not robotic.
Hidden Depths: During the "Green With Evil" multi-parter, Alpha - as Zordon says - "displayed exemplary leadership capabilities." He even trapped Evil!Tommy, and it took Rita's magic to free him.
Large Ham: Literally—he can grow to fight alongside Megazords and has a larger personality.
Long Bus Trip: Stopped appearing after "The Sound of Dischordia" due to the use of the Orb of Doom in "Rangers in Reverse." Later in "A Zeo Beginning, Part 2," it was stated he was "back in the temple." He hasn't been seen since.
Badass Normal: Bulk held the record for most reps at the Juice Bar with 1,000. He was only beaten by Jason after several attempts.
Characterization Marches On: Bulk and Skull were originally the school bullies of Angel Grove High, but as the show went on this aspect of the duo was downplayed and eventually they became more like class clowns.
Let's Get Dangerous: On at least one occasion, Bulk and Skull defeat a monster themselves, after the Rangers themselves are defeated. Nobody believes them afterwards when they brag about it, however.
Relationship Upgrade: A debatable one for Skull's crush on Kimberly. Never brought into canon, but writer Amit Bhaumik said in a 2005 interview that he had wanted to have Kim be married to Skull in the episode Forever Red and name Kim as the mother of Skull's son Spike. While unofficial, the idea is popular with some fans and the actors on the show have referred to the relationship when discussing the show with fans.
Smarter Than You Look: In Season 2, they try to discover the Rangers' identities... and most of the times, they are really close, but the Rangers screw up their work.
Skull, of all people, is a classically trained pianist. He's absurdly good at it. Becomes a central point of Character Development between him and Bulk as the big doof initially derides Skull for it, but by the end of the episode Bulk changes his mind and shows that he can be supportive of him like a real friend should.
Weirdness Magnet: No matter the Evil Plan, no matter where in Angel Grove the attack is taking place, odds are Bulk and Skull will happen to be nearby when things go down. Their interactions with monsters occurred so often that Lord Zedd knew them by name. This trope was eventually Lampshaded in Season 3:
Lt. Stone: I find it very odd that you two are the only ones in Angel Grove outside of the Power Rangers to face off with a different monster every week!
Skull: Lt. Stone, it's true. Every time we turn around, well (sputters), there they are.
Bad Boss: When the Rangers defeat the latest monster, she's prone to taking her frustration out on her underlings - even if they had absolutely nothing to do with what went wrong.
Machiko Soga: Actually came back after finishing Zyuranger to do a few scenes speaking English as Rita so the dubbing would fit better (though it still wasn't perfect). Later, she even redubbed herself to voice Rita for the Japanese dub of the series.
Suffering For Your Art: Voice actor Barbara Goodson was getting jerked around by Saban during pre-production. She was given the part, and told to voice Rita like the Wicked Witch. She did, and was fired. They decided to try to make Rita sound angrier, and rather than let Goodson try, they forced her to reaudition. According to her, she did, and said, "You want angry? [Rita's screech comes out of nowhere] I'LL SHOW YOU ANGRY!" Not knowing she would have to do the part for seven years. She mentioned going through a lot of water and cough drops, and we thank her for suffering through.
The Dog Bites Back: Throughout Season 1, Goldar was Rita's most loyal sycophant despite her constant verbal and physical abuse of him. Lord Zedd's taking over in Season 2 changed that. Now, given Zedd's Man Behind the Man status, Goldar expressing loyalty to him made sense. However, Goldar also proceeded to mock Rita to her face, claimed that he had always criticized her for her failures and took great pleasure in her dumpster exile. When she came back and married Zedd, he was still noticeably terse towards her.
Arguably more so in Season 2. At least Season 3 gave him the benefit of some victories (such as beating down Ninjor, which helped lead to his capture). Season 2 saw him routinely defeated in battle, even once by an unmorphed, powerless Tommy.
Squatt & Baboo | (Voice actors: Michael Sorich and Colin Phillips)
Demoted to Extra: In the third season, when Rito and Goldar took their place as the bumbing duo.
Note that they essentially served as Rito and Goldar's de-facto minions, which was arguably an improvement. In the second season, all they seemed to do was cower in fear of Lord Zedd or get yelled at by him.
Evil Counterpart: To Bulk and Skull, to the limited extent that one pair is evil and the other is good. Lampshaded by Rita the first time she saw Bulk and Skull:
What Could Have Been: "Goldar's Vice-Versa" wasn't going to be her last appearance, as there were plans for her to return later in Season 2. However, chiefly, the failure to secure the American actress for more than one episode led to abandoning those plans.
Body Horror: He has no skin, his brain is exposed and who knows what's behind that face plate. It's been implied that the Zeo Crystal's forcefield did this to him when he tried to claim it.
Evil Cannot Comprehend Good: Some of his schemes involved trying to pit the Rangers against each other or trying to break their spirit by endangering others. His efforts only had the exact opposite effect, which always stunned him.
"I don't understand it. The more I divide them, the more they come together."
Executive Meddling: Not of their own choice but parents found Zedd to be too scary at the start (who could blame them, in the introduction in addition to his appearance. The guy had a snake wrapped around his arm.) Thus had to tone him down later to make him more of a laughable villain. It's wasn't too much to dampen his character as he was still a force to be reckon with however.
The Man Behind The Woman: At the start of Season 2, it was revealed that Rita answered to Lord Zedd and was charged with conquering Earth for him. Her failure led to him taking a more direct role.
Orcus on His Throne: This trope goes for any Ranger Big Bad, really, but it becomes really evident when (as noted above) Zedd effortlessly clobbers Tommy.
The Bad Guy Wins: Zedd accomplished a lot of things when he married Rita, like capture Ninjor, nearly kill Kimberly, allow Rita's brother Rito Revolto to destroy the Thunderzords, blowing up the Machine Empire in the Power Rangers Zeo finale "Good as Gold", just to name a few.
Chuck Cunningham Syndrome: Was last seen at the very end of Zeo and never returned. Real Life Writes the Plot, as his suit fell into disrepair. It reportedly had to be patched up more than once during Zeo.
Screw This, I'm Outta Here: At the end of "Alien Rangers of Aquitar", after the Aquitan Rangers defeat his latest monster, Vile decides to head back to his own galaxy, much to Zedd's delight.
The Bad Guy Wins: Apparently the case in his own galaxy, as states before running off that he's going back home, where the bad guys can WIN.