One of the most genuinely interesting things about K. Rool and the Kremlings is that they're bit of a Krystal from Star Fox case in that they're remnants of an cancelled original property Rare was creating that ended up getting crammed into a Miyamoto helmed Nintendo IP.

It was called "Johnny Blastoff and the Kremling Armada" and was supposed to be some sort point and click adventure game for PC. but then it got shelved and Rare decided to recycle some of its character designs for DKC when Nintendo instructed them to create original antagonists (their original idea was to use Wario, funny enough).

https://www.unseen64.net/2017/12/27/jonny-blastoff-kremling-armada-rare-pc-cancelled/
https://www.svg.com/1232756/donkey-kong-countrys-original-pitch-featured-wario-as-the-main-villain/