One of the most iconic anime in history, Doraemon has run for over 2,600 episodes so far. For the sake of comparison, America’s cultural mainstay The Simpsons is just past episode 600, so, even if you make a claim that “The Simpsons already did it”…
…odds are Doraemon did it first.
Episode 241, from 1980, has the gang meeting up with King Kong himself… sort of. They’re out on a trip into the country, and encounter a regular-sized primate. Doraemon brought a lunch along, keeping it portable with his shrink-ray, and they accidentally zap the monkey with it, causing it to grow into “King Kong”. The ape terrorizes the kids for a while, then it accidentally uses the growth light on Goda (who’d just fallen in the grass to look like Gaira), leading to a monster battle….or, more like a game of tag, as Kong runs away pretty fast.
It’s not a terribly substantive episode (Doraemon seldom is), but it’s a fun footnote in the intersection of Kongdom with anime, and I don’t see it brought up very often.