Cutest BAMF right here. If there's a evolution of him being Snorlax/Hariyama tier but with all them kung fu moves, you can bet your ass I'm getting this little guy and whoop some butt with him. And hug him for all eternity when he does evolve.
Japanese doesn't have an explicit letter for M. The closest they have is Mu (sometimes Mo). Often when a name ends in U, the U is supposed to be silent, but you can't be sure of that of course. So it could be either Yancham or Yanchamu.