mammals are mostly viviparous (giving birth to live young), but there are a few notable exceptions . The Platypus (Ornithorhynchus) is specifically identified as an oviparous (egg-laying) mammal . In contrast, the other animals listed—the flying fox (Pteropus), elephant, and whale—are all examples of viviparous mammals . This specific question has appeared in previous medical entrance exams such as the AIPMT 2015 .