According to character designer Gregg Mayles on Twitter, after the announcement that King K. Rool would be in Super Smash Bros. Ultimate, a character that Gregg had named and designed the actions of, he revealed that the character was original called "KOMMANDER K. ROOL" and that Donkey Kong Country was originally to be called MONKEY MAYHEM. He also mentioned that the "K." in K. Rool does not actually stand for anything and the name itself is only intended to be a play on the word "cruel", though he joked that the initial could stand for something mundane and off-character, such as "Keith".

In addition, Gregg's brother Steve, who designed the look and visual design for the character, also revealed that the programmers thought King K. Rool was "too big" and too taxing on the game's memory, and thus several frames of the character's animation had to be dropped as a result.