Embryonic morphogenesis involves sustained plastic deformation of the tissues, the composite material built up from cells and extracellular matrix. Tissue flows are driven by cellular activity such as exertion of contractile forces or the controlled formation and release of intercellular mechanical contacts. We introduce a cell-resolved computational model that yields elasto-plastic behavior and also allows the representation of various cell activities such as active intercalation, contraction or bending. We compare model simulations with empirical motion data onmesothelioma nodule formation, convergent extension and early heart morphogenesis.