Agile methodologies can be enhanced by the use of shadows as this fea- ture because of its inherent ability to dynamically change the behavior of classes and objects, provides mechanisms to ease common tasks such as prototyping, deprecating, dynamic classification and interclassing at run-time. We feel however that shadows should be considered a notion beyond any specific programming languages, so that they can as well be integrated in model-driven software engineering. Therefore we introduce Shadows-UML, an UML extension, that would help to push forward the convergence between model-driven and agile methodologies.