  Planetary nebulae (PNe) exist in a range of different morphologies, from very
simple and symmetric round shells, to elliptical, bipolar, and even quadrupolar
shapes. They present extremely complex ensembles of filaments, knots, ansae,
and shell multiplicity. It is then overwhelmingly complicated to derive
reasonable evolutionary paths to justify the observed shapes of PNe. The
confrontation between the evolution of the shells and that of the central stars
is needed to understand the origin of the morphological variety. We present
some background and recent results on the correlations between PN morphology
and PN nuclei (PNNi) evolution, including a study on the Magellanic Cloud PNe.
