Are we going to see Ninja's in One Piece ?

Oda sensei had already introduced Samurai's in op.
So do you guys think he will introduce Ninja's as well. Obviously, it won't be the typical Ninja that we see in TV, movies and internet memes. These Ninja's will have a certain One Piece flavor to them. Just like with Pirates and the Samurai's.
May be in Wano Country !