My friend TESS tells me there are two registered trademarks for the single word mutant... #78472727 Rednex Inc in S. Carolina for motorcycle frames #78264724 AI BEAU CO., LTD. in Osaka, Japan for eye/sunglasses, goggles, etc now Marvel does have or (had) Mutant X, New Mutants, Mutant Gear, X-Men Mutant Gear, etc registered but there is no record that they ever had or even applied for a trademark on just plain "mutant"