Speaking of DKC, I'm surprised nobody has ever tried to mod DK into DKC2 or Dixie into DKC - I understand that it's way more complex than just copy and pasting over some graphics and code, but still feels like one of the first things people would've tried to do upon the development of SNES ROM tools given the popularity of stuff like Knuckles in Sonic 1 and flying Tails in Sonic 2 mods.
Still, we don't necessarily need this.