There is a degree of variability in the results of this crossing but some characteristics are almost always present, the hybrid adults are larger, especially the females and there are frequently deformities. Commonly they have the crest markings of the marbled newt and the body markings of the crested newt
Biologically the males are sterile and the females partially fertile. When the hybrid females breed with either T. cristatus or T. marmoratus they produce around 650 eggs a year which is double that of T.marmoratus and triple that of T. cristatus but the survival rate is very low.
They can be found in Basse Normandie, Pays de la Loire, Centre, Ile-de-France, Poitou-Charentes and Limousin.