This book summarizes the current state of knowledge about Heloderma suspectum through analysis of recently published scientific literature and integration of breeding outcomes provided by international breeders along with the authors own experiences and observations to form a an up-to-date understanding of this lizard species. In addition to the chapters on biology, in which the habitat, its flora and climatic conditions are presented, as well as anatomy, the book provides detailed instructions on the captive husbandry, reproduction, health issues and finally, the rearing of juveniles. The venom apparatus, the medical use of the various components of Heloderma suspectum venom, the risk of envenomation and the treatment of such a case is also covered. A total of 390 photos, drawing or diagrams are used to illustrate all the major details presented in this book.A chapter on the evolution of helodermatids authored by paleoherpetologist Krister T. Smith of the Senckenberg Museum Frankfurt as well as an extensive contribution by the US-American lizard specialist Aaron M. Bauer (Villanova University) on the Knowledge and iconography of the genus Heloderma until 1900 completes the book. The preface by Karl H. Switak attests to the fact that Dr. Hans-Joachim Schwandt has acquired much of his knowledge about reptiles in natural habitats during his many trips during which he was accompanied by American friends. Last, but not least, the dynamic US contacts he has maintained for decades made it possible to gather valuable information and photo documentation prior to the completion of this book.