The fact that every pokémon, with few exceptions, can learn Toxic, Double Team, Protect, and Substitute leads me to the (fallacious) conclusion that all pokémon are ninjas. In a setting where their entire purpose is battling, well, I guess they are by a loose definition. If Joe & Mac are caveman ninjas, why not pokémon?
I don’t know who Joe and Mac are and I suspect I don’t give a $#!t
But, well, we explicitly know that Toxic is a ninja technique from Koga, and Double Team and Substitute (and Protect? Don’t know about that one) seem to be based on legendary ninja techniques. Perhaps more importantly, that makes them human techniques, which means Pokémon can do them regardless of which bull$#!t magical powers they happen to have, or even without necessarily having any bull$#!t magical powers at all.