I've been trying to wrap my head around the use of the word "mutant" (not the X-Men characters/franchise/etc., which clearly is licensed to Fox). There seems to be a boatload of speculation and, in my honest opinion, misinformation floating around. Marvel representatives often dodge the issue without directly addressing it - and example can be found here . Note that, 

Misconception 1: Fox owns the rights to the X-Men. This is false. They have licensed the intellectual property from Marvel. Marvel owns it, and the conditions of its use are confidential.

Misconception 2: Fox owns the term mutant. This is actually a little more ridiculous. There might be a secret deal between Marvel and Fox that restricts the use of the term in reference to Marvel Studios properties, but I highly doubt that.

Why, you ask? Because of a little show from 2001-2004 called Mutant X. You see, back in the summer of 2000, Marvel worked with some other entertainment companies to put this show together with some characters that got their powers via experimental genetic engineering (rather than natural mutation). These characters were refered to as New Mutants, and the team was Mutant X.

Fox sued everyone involved - of course they did. However, the suit was over two things:

  1. The name Mutant X was too close to X-Men. The court ruled that they are, in fact, similar, but refused to grant an injunction on the show, which ran for 3 seasons.
  2. That the content of the show was too close to that of X-Men.

In the course of the proceedings, not once was it ruled that:

  • Marvel cannot use the term mutant (the issue of the X-gene and the like, however, was not in play)
  • Fox owns the TV rights to the X-Men franchise (the Generation X TV pilot from 1995 was actually produced by Marvel)

In fact, the original contract (from 1993) gave Fox a right of refusal on X-Men themed shows, but explicitly denied Fox the right to produce them.

The slew suits were settled in 2003 (at least between Fox and Marvel) - well before the final season of Mutant X aired. The show was cancelled because one of the studios went out of business, not because of the lawsuits or any legal reason I can find. They legal disputes between Tribune, Fireworks, Marvel, and Fox (except directly between Fox and Marvel) continued after that due to disputes about who sold who what, character and plot similarities, etc.

However, and this is important to reiterate, nowhere in any of these cases is the term mutant itself addressed. That piece might have come out of the 2003 settlement, but than why would Mutant X have continued for another year plus?,1002,271%7C69831%7C1%7C,00.html