Hey... isn't diddy kong 3rd party?

May be a noobish question but i'm confused, DK was made by nintendo but diddy was made by rare isn't it? or am i confusing things?

I mean, rare made the DS game diddy kong racing, but DK is nowhere to be found, so i had that thought, hope you guys clear it for me, don't bash, i really don't know.

Diddy Kong (along with all the other extra kongs), were created by Rare. However, when Rare split from Nintendo, Nintendo bought out all the characters and rights to Donkey Kong and it's related games.

So while Diddy Kong was not created by Nintendo, they own the full rights to the character.