A fast-food joint should come out with MAMMOTH BURGERS, but have them be normal-sized, just using un-exctincted mammoth meat.
They can be smaller than normal, purposely named incorrectly by size, but legally okay, because of the animal used.
It would just make sense.
Now, I am not a lawyer, so take this with a grain of salt. But I work a lot with our company legal team because they have to vet anything that we publicly release, so I feel like I've got a decent sense of what makes them uncomfortable... There are areas where they call out specific things because they're legally defined. There are a LOT of other things where they ask questions just to make sure that we have the evidence / logic such that if we're questioned on a claim, we can justify why / how we came up with it.
"Mammoth" is not a legally defined term (outside of the extinct animal, of course). You could call a burger a Mammoth Burger, or a Gargantuan Burger, or a Colossal Burger, even if it was the size of a slider, without legal fear. The
market will crush you and the
internet will call you stupid names if you do that, but I doubt any lawsuit would stand up in court.
However, if you use something that is legally definable, and then don't live up to it... That's a problem. For example if a company came up with a 1/3 lb burger and it was found out that they were only using 1/4 lb of beef... Oh yeah, you're screwed.
BTW that's why you'll typically see a little asterisk, and a footnote for the asterisk, saying it's "uncooked" weight. Because they can't perfectly predict the amount of moisture loss during cooking, so as long as they know they started with 1/3 lb (~5.3 oz) of meat, you can't sue them if you take the cooked burger patty off the bun and it only weighs 4 oz.
In fact, the only problem with calling a burger a "Mammoth Burger" is that a nervous lawyer would force you to asterisk/footnote it saying that it isn't woolly mammoth meat
