A 2003 US case I was somehow unaware of on whether or not the X-men and various other beings are human beings: https://www.cit.uscourts.gov/sites/cit/files/slip-op%2003-2.pdf.

It's a customs duty dispute over whether they are 'dolls representing only human beings' or 'other toys representing non-human creatures'.

"Whatever the degree is to which they resemble human beings, the court finds that these action figures do not represent human beings and are therefore not properly classifiable as “dolls” under HTSUS heading 9502. The court bases its finding on at least three observations. "

"First, most of the figures at issue exhibit at least one non-human characteristic. The court does
not agree with Customs that the few non-human characteristics the figures possess, such as claws
or robotic eyes, “fall far short of transforming [these figures] into something...

...other than the human beings which they represent” because the issue under the HTSUS is not a straight headcount of the human features a figure may possess, rather the issue is whether the figure as a whole and in a wider context represents a human being."

"Second, these characters are known as “mutants.” That fact further informs their classification. They are more than (or different than) humans. These fabulous characters use their extraordinary and unnatural physical and psychic powers on the side of either good or evil."

"Third, the “X-Men” figures are marketed and packaged as “mutants” or “people born with ‘x-tra’ power.” That they are denoted as such lends further credence to the assertion that they represent creatures other than (or more than) human beings."

"More importantly for the purposes here, the category “mutants” is like the categories of “robots” or “monsters.” The categories of “robots,” “monsters,” and “mutants” are all, even if humanoid, extra-human (or non-human) categories of being."

""The court next turns to the more difficult classification of the action figures referred to as “Fantastic Four.” The assortment 45100 is comprised of the “Fantastic Four” action figures “Black Bolt,” “Mole Man,” “Terrax,” “Mr. Fantastic,” and “Silver Surfer.”"

"the court finds that the four “Fantastic Four” figures do not represent human beings. The last figure in this
series is truly a close call. “Mole Man” is described as both being human and having an “odd appearance, extraordinary intelligence, cunning, and fighting prowess"

"Given the entire context of the figure’s appearance and fantastic story, and the fact that it is part of a series where the characters are described as “super-human,” the court finds that “Mole Man” is also not properly classifiable as a “doll” under the HTSUS"

"The court next considers the items collectively referred to as “Spider-Man” action figures, two of which also pose more difficult determinations than the mutant figures of the “XMen” series. At issue are essentially 4 figures, “Hobgoblin", “Dr.
Octopus", “Kingpin" and “Kraven."

"Both Hobgoblin and Dr. Octopus have supernatural powers. The other two figures are more difficult to classify. The figure of “Kingpin” resembles a man in
a suit carrying a staff. Nothing in the storyline indicates that Kingpin possesses superhuman
powers."

"Even though “dolls” can be caricatures of human. beings, the court is of the opinion that the freakishness of the figure’s appearance coupled with the fabled “Spider-Man” storyline to which it belongs does not warrant a finding that the figure represents a human being."

"The last figure in the “Spider Man” line is “Kraven.” According to its packaging, Kraven is the “last of a dynasty of Russian aristocrats” and “trained himself to be the greatest hunter on Earth.” He uses “secret jungle potions” to “augment[] his strength and
stamina.”"

"“Kraven” is the representation of a mythical or legendary creature more properly belonging to the list of robots, monsters, angels, and devils (which have been expanded by Customs to include trolls), rather. than being a representation of an ordinary. human being."

"Plaintiff withdrew from the case the items “Daredevil,” “Invisible Woman,” “Punisher,” “U.S. Agent,” and “Peter Parker,” and Defendant agreed to classify the items “Beast,” “Bonebreaker,” “Cameron Hodge,” “Robot Wolverine,” and “Vulture” as “other toys,”".

"The current action may have retrospective practical effect only. Although the most recent HTSUS (2002) retains the distinctions in the “toys” classifications, the court notes that all of the “toys” provisions including the “dolls” provision now have the same duty rate"."

One of many fascinating US customs disputes. See also:

- are ouija boards only a game? No, says Hasbro packaging. Yes, says US appeals court. No, says UK Court of Appeal (Criminal Division.)

- are tomatoes fruit? Yes, say biologists. No, say cooks. No, says US appeals court.

Related: a US evidence law split on whether the music of Enya is 'soothing' (and hence permitted background music for a video victim impact statement at a capital sentencing hearing) or 'stirring' (and hence not.) The USSC refused an appeal from a pro-'soothing' judgment.