Phenotypic switching is switching between multiple cellular morphologies.
Phenotypic switching in Candida albicans changes the cells from white to opaque in need for sexual mating.
A second example occurs in Melanoma, where malignantly transformed pigment cells switch back-and-forth between phenotypes of proliferation and invasion in response to changing microenvironments, driving metastatic progression.
References
Phenotypic switching Wikipedia(Text) CC BY-SA