Wandering domains in non-archimedean polynomial dynamics

We extend a recent result on the existence of wandering domains of polynomial functions defined over the p-adic field C_p to any algebraically closed complete non-archimedean field C_K with residue characteristic p>0. We also prove that polynomials with wandering domains form a dense subset of a certain one-dimensional family of degree p+1 polynomials in C_K[z].