Marvel were never adverse to cashing in on trends and Danny Rand's origin comes from the mid-seventies boom in all things kung-fu brought on by the emergence of Bruce Lee. Iron Fist was added to Master of Kung-Fu in the company's arsenal and became popular enough that when the inevitable decline came he was paired up with Luke Cage in Power Man and Iron Fist, where he was killed off in the final issue. Naturally he was resurrected (via the "it was a double" get-out, nice one nineties Marvel...) and has since been one of those characters that are popular but never quite big enough to properly support a series, though the huge current interest in all things Marvel that aren't actual comics means he's destined to get his own Netflix show soon.
One of the other places he found a home as a supporting character was the Ultimate Spider-Man cartoon series, which was mined by Lego for sets. That version of the character, a teenager, received a Minifigure in the updated costume, which is a bit of a shame - the original seventies one was very much of its' era and had a bit of a variety to it; broken down to Lego form the guy just has a dragon on his chest, with even the wrapped head not really coming across very well. But then it's an Iron Fist figure from Lego so it would be harsh to complain overly.
The figure has been bootlegged but while most reproductions are fairly close the Iron Fist one suffered from a big problem when the lower half of his face was left unpainted, i.e. yellow. This meant that not only did the mask look weird but it really set off my OCD compared to the rest of the flesh-toned Marvel figures, leaving me with little choice but to actually pony up for the real thing. Bah.