I've been playing a lot of the Mario Kart DLC lately and loving playing as Petey Piranha. I almost forgot he existed because he has been in like three games since 2009
sidenote: Anyone remember Toadsworth? The last time he was in a new original Mario game was in 2013. How many Mario characters were killed off in the era of Koopalings? There's gotta be way more than these ones
The devs on Paper Mario: Origami King noted (complained?) that they weren’t allowed to introduce any new character types, or even vary significantly on the established character types. Nintendo can be weirdly neurotic about protecting/limiting their IPs.