edit: Didn't realize when I wrote this that someone else already addressed my exact issue and was met with agreement. Nothing to see here.

"The key difference between this and Captain Ersatz is that an Expy is not clearly supposed to be the character, but is rather very similar, while Captain Ersatz is obviously the same character but with the Serial Numbers Filed Off."

Okay, that's not enough an explanation, for in many cases there's difficult to distinguish whether a character is supposed to be a very similar character, or the same character in a "generic" version. For example the Watchmen characters are both listed as Expys and Captains Ersatz, and you can make a strong case for both sides. And many others as well.

Exactly how is "expy" short "exported character"? "Exported" I get but not "character". This is made even worse since the split is between the "x" and the "p". I don't know about you guys but I see neither a "p" nor a "y" in "character".

The picture of the Family Guy, American Dad, and Cleveland Show characters is cute, but it's really not a good example of expies. The characters fit the same general niche, but are otherwise very dissimilar and clearly aren't "unambiguously and deliberately based on" each other.

Peter, Stan, and Cleveland may all be "lovable idiots" but saying that makes Stan and Cleveland expies of Peter is like saying the Avengers are expies of the Justice League because both teams have "a square-jawed leader (Superman/Captain America); a billionaire who considers himself the real brains of the group (Batman/Iron Man); an archer who's romantically linked to a woman with a bird in her codename (Green Arrow and Black Canary/Hawkeye and Mockingbird); a woman with ill-defined magical powers (Zatanna/Scarlet Witch); a non-human from a long-dead culture with incredible power (Martian Manhunter/Thor); a king of Atlantis (Aquaman/Sub-Mariner); a speedster (Flash/Quicksilver); a scientist who can change size (Atom/Hank Pym); and an android (Red Tornado/Vision)."

It's an amusing picture and I get the desire to find a place for it, but it's pretty misleading to use as an illustration of the concept of "expy."

What is the opposite trope of Expy?

Battlestar Galactica, Merlin and 2010 Star Trek all use name from the Original story, but tell a different story altogether.

Similar to the Star System question above- should there be any distinction (or separate trope to be made) for when a creator uses Expies of their characters consistently, like the Seth Mac Farlane image on the page shows? In my mind it's always been a totally different matter for a writer/artist to make references to their own past characters than to make references to others'.

What exactly distinguishes this from AlternateCompanyEquivalent? It doesn't really appear to be made very clear on either of the pages, although Captain Ersatz does get a slightly more clear distinction on this one...

Shiro. Red-eyed superpowered girl with mysterious forgotten past relation to the main character, as well as traumatic past, imprisoned for several years, and a dual personality: one murderous and menacing, and the other braindamaged and childlike. What say we give her hair a little more pink and substitute her vocabulary with "nyu"?
Expy, or Captain Ersatz?

What about when a gender change is involved? Is that still this trope? e.g. Tasuki from Fushigi Yuugi and Rei Hino/Sailor Mars from Sailor Moon. Both have fiery personalities, are best friends to a main character (Tamahome & Usagi respectively), use fire/ofuda scrolls in battle, and even their fictional birthdays are just a day apart. Naoko Takeuchi and Watase Yuu must've had more than a few meals together planning/giggling about these two back in the day.

So here's something I'm wondering, because I've seen it around: do Star System characters count as Expies? There's a couple of them listed, like Miyazaki's works, that are obviously cases of a Star System. Should we clean those out and put an explination of the difference in the two entries?

• One Piece recently saw the protagonist of one of its creator's earlier stories(Monsters) appear as a zombie swordsman. In fact, the country that Monsters takes place in is mentioned in so many plot points that it is pretty much a part of One Piece canon.
  • There's also the character of Monkey D. Garp who is Luffy's Grandfather. Originally, Garp was a character who appeared in one version of the pilot Romance Dawn. In this version, he was the one who gave Luffy the Gomu Gomu Fruit and he also was the one who inspired Luffy to become a pirate. Ironically, his current self frowns upon Luffy's pirate lifestyle.

This sounds more as Canon Immigrant.

• An ironic expy: Dawn's Mamoswine, of Ash's Charizard. Both are final stages of a Pokémon that evolves twice, both were caught in their first forms, both started to disobey their trainers after evolving to their intermediate form, and both went from their base forms to their final forms ridiculously quickly (Ash's Charmeleon evolved to Charizard just three episodes after evolving from Charmander; Dawn's Piloswine broke that record by evolving to Mamoswine just two episodes after evolving from Swinub). This is ironic because Charizard is a Fire-and-Flying type, and Mamoswine is an Ice-and-Ground type. However, while Charizard didn't start obeying Ash until 61 episodes after it first started disobeying him, Mamoswine comes around in just 13. The reason for changing their tune was the same, though

Outside be desobedient the two have something in common? Piplup sounds closer to a Pikachu Expy than Mamoswine to Charizard.

• Hell, arguably Grobyc can be considered an expy of Robo.

The two have something in commom outside the "species"?

• Black Mage from Eight Bit Theatre will be in another webcomic hosted on the same site, How I Killed Your Master.

This is only Canon Immigrant.