I think you're misunderstanding what falls under plagiarism when it comes to character design. I went and looked up a bit on copyright law and infringement in both of the relevant countries to this case (US and Australia), making sure the information came from actual government websites and law offices before I decided to reach out to the companies involved, specifically so I could be absolutely sure that this was indeed a case that would legally fall under copyright infringement.
In the United States of America, where Zamination is based (or at least that's where it says they're based on their wiki) infringement of an original user's IP is based on a few main things:
Did the potential plagiarist have reasonable opportunity to view or encounter the original work before creating the allegedly infringing work? - Answer: Yes. Modmad's comic has been openly available online since 2012.
Is there substantial similarity between the two works, measurable by specific criteria such as dialogue, plot, character development, OR (important to note that it is 'or', not 'and') visual composition?" This means that their stories/backgrounds don't have to be the same for it to still be copyright infringement on the character design itself. And yes, they have very many identical points in their character designs, some that were UNIQUE to Modmad's RGB that differentiated him from other versions of TV head characters (and aren't seen in any other TV head character I could find, as shown in the image of over 40 additional characters I added in my original reply to show the variety of different designs people have come up with). Whether their stories/lore are different doesn't have any bearings on the issue of plagiarism in this case.
Does, or would, a lay observer recognize the infringing work as a copy, or at least as substantially similar, to the original artist's? Yes, and that's been demonstrated by the individual accounts from separate people, both from fans of SMG4 AND TPoH, which can also be seen included in my reply.
Additional notes on copyright infringement in America, as laid out by an IP focused law firm in New York:
Offenders can still face liability for copyright infringement if overall sequence, structure, and expression are substantially similar, regardless of if they have changed names, settings, or minor details.
Fair use only applies if IP is used for criticism, commentary, news reporting, teaching, scholarship, or parody. 4 factors are taken into consideration for potential fair use cases: The purpose and character of the use, the nature of the copyrighted work and offending work, the amount and substantiality of the portion used, and the effect on market or value of the original work.
Transformative works, which alone do not guarantee fair use, are not viewed positively in a legal sense if the offender has copied the heart of the original work or their most valuable/distinctive portions, regardless of what else may have been changed.
There may be leniency in 'good faith' cases where the offender believed they were practicing 'fair use'. However, willfulness is a critical distinction in IP law for the courts, so if they were made aware of the copyright issue and continued to recklessly disregard the rights of the copyright holder, than that argument of 'good faith' flies right out the window (which in this case, it would, since Modmad has been reaching out to them for 2-3 years).
Copyright infringement focuses on two aspects of damages done - actual damages, and statutory damages. While actual damages are the actual profits lost plus the profits gained by the offender, statutory damages are granted solely on the fact that the copyright infringement happened at all, and according to the website mentioned, can range anywhere from $750 to $30,000 per work infringed, or even up to $150,000 per work if the infringement was knowing and willful, even if no actual market harm was done to the original copyright holder. Unless they're able to prove that they sought legal counsel once the issue was brought to their attention, that falls under suggested insufficient care in holding up copyright law.
In Australia, where Glitch and SMG4 are based, they have similar copyright laws and standards for copyright infringement:
Has a whole or 'substantial' part of the copyrighted work been used? Infringement can occur even if only a part of it has been copied, as 'substantial' refers to quality rather than quantity. Even a small but important or distinctive part may be substantial enough to qualify.
Did those who made the 'copied' work have a connection with the copyright-protected work? This can be true simply if those who created the 'copied' work could have had access to the copyrighted work (ie if it was freely available online, for instance).
Is there an objective similarity between the original copyright protected work and the copied work?
The government website for the Australian copyright standards, which is where I got the above, also includes the following 'common misconceptions' on copyright infringement:
“I changed it by 10%, so it’s not infringement.” There is no percentage rule. Even small portions can infringe if they are an important or distinctive part of the original work.
“I gave credit to the creator.” Attribution does not prevent infringement.
“It was only for personal use.” Personal use is not a general exception to copyright infringement in Australia, though specific exceptions may apply.
“I found it online, so it’s free to use.” Works found online are still protected by copyright law unless it is in the public domain or under an open license.
Now that legal stuff is a bit out of the way, I wanted to get into your actual individual points that you noted in your reply.
"My fiancé thought RGB and Mr. Puzzles both look a little like this Bo Burnham character from this Welcome to the internet fanvideo (2022)"
Even if that were the case, the fan video was also made a decade after RGB, so has no place in whether or not its design has impacted either RGB or Mr. Puzzles.
Other than being TV Heads and wearing a 'suit' (in the vaguest and most general sense of the word), there are no additional similarities that can be pointed out between these characters.
Not even going into the fact that the Bo Burnham robot is just an outline, there are a NUMBER of differences that make it unique from the other two designs. Having so many similarities that they can't be (and haven't been) ignored, like with Mr. Puzzles and RGB, is when it falls into plagiarism risk territory.
"And yes, their design has quite some similarities, but if I may: None of them are that original in the first place."
I beg to differ. Modmad has been widely complimented and given credit for the originality of RGB's design over the years. And if you look into compliments for Mr. Puzzles' design, you'll find that they're parroting the same when complimenting 'his' design (typically noticing the color bars smile, and the way that it drips), so even SMG4 fans have come out to say that those ideas and elements of the character design are innovative and unique. You can see this pretty easily by taking another look at the list of TV head examples I gave, because NO other character on that list - including the example you just tried to give - have a color bars smile, much less one that drips physically out from the screen. While one or two elements being the same may be a coincidence, the likelihood that MOST of their traits matched each other so closely just randomly out of the blue like this, especially traits that have DEFINED RGB from his conception, is slim to none. And honestly, if you can't seem to tell the difference in the level of similarities between RGB and Mr. Puzzles vs the Bo Burnham robot, I'm not sure you're the greatest authority on discerning if these designs are actually original or not to begin with.
"Nobody would design a character with a flat TV because it simply doesn’t have the same charm, and artists stylize them to look distinguished and cartoony"
Gonna be honest, not sure how to respond to this. This is kind of telling me that you didn't actually look at any of the arguments or evidence provided before deciding it was wrong.
There are this many just in the list I provided alone - Vox in the upper left is arguably one of the more well known TV heads at this point in time, and he is, for sure, a flat screen TV.
Like, for heavens sake, SMG4 has their own flatscreen TV head, for crying out loud.
"So while vents on the side might not have been that common in the real world, I don’t think Mr. Puzzles was modeled after one particular TV in the first place--but rather, a bunch of them."
This is nothing more than speculation on the process and intentions behind Mr. Puzzles creation. You don't know the facts of that process, and neither do I, so arguments like that don't have any weight in this conversation. None of that changes the fact that the similarities between the two designs exist in a relatively high number, and that along with the reactions to them from a general audience causes it to fall well within the parameters legally set to define copyright infringement and plagiarism.
"But that aside, even if you don’t see my argument and think these characters look too much the same, so what? We all build on the shoulders of giants. It is very hard to create something that has never existed before. So what’s the harm in getting a little inspired?"
From how blasé you're acting about the situation, I'm going to assume you're not a creator. Or at least, you're not one that has any actual stakes in the creative field, or any attachment to your own creative works (if you want to claim that you do, then fine, you're just a hypocrite). This is not 'building on the shoulders of giants', it is a larger company/group that has taken a design from a smaller independent creator. This isn't 'inspiration', it's seeing a character with an innovative design, and going, 'Oh, I'm taking that and saying I came up with it!' It's nothing more than theft, plain and simple.
And if you want to talk about what Mr. Puzzles has built that's solely from himself? From SMG4 fans specifically, I have seen comment after comment after comment of fans lamenting how lackluster his character and arc were at the end, especially since they had gotten so excited because of - wait for it - HIS GREAT CHARACTER DESIGN. And these were on FAN pages and posts about Mr. Puzzles, by people who loved him. Though there are those who enjoy his 'silly' personality, by and large the most compliments I saw being given to him were mainly for his looks. So if his looks are his greatest asset, you see how that becomes an issue all over again in terms of what was gained by basing his design off of someone else's work?
Now, I laid all of this out just on the off-chance that you genuinely didn't understand the specifics of copyright infringement or plagiarism. From your username, I am more than aware that you are an SMG fan and likely are just trying to support a company that you've been following and enjoy. However, just because you are a fan of something doesn't mean you should dismiss criticisms against them without doing even the smallest amount of actual research and jump straight into basing your opinions on nothing more than 'well I like them so it must be okay', while trying to simultaneously implement 'gotcha!' arguments without fully understanding the logical fallacies that lie behind them.
Morals and acting to do the right thing sometimes means recognizing when something or someone you're fond of or a fan of has potentially done something wrong, and holding them accountable (or at least researching the topic a little, jesus). If that's not the intention behind your actions and you don't actually care about the moral or right thing to do so long as you get to keep enjoying what you enjoy, then we have very different values and approaches to life and this conversation won't really be able to go much further.
