Download Egg Laying Mammals Are Called PNG. Milk fills shallow depression in place of nipples. Yes, there are egg laying mammals and they are known as monotremes. I'd argue that the main reason why mammals have become so successful is due to their phenomenal evolutionary jump from laying eggs (oviparous) to birthing live. The other one being the platypus. Egg laying animals called oviparous. The development within the egg is very brief, and in all other aspects, the monotremes as they are called, resemble other mammals. Johnny storm, who was briefly married to a skrull named lyja (long story), was greatly disconcerted when she. The other four are species of echidna (a mammal that looks a bit like a porcupine). They include paltypus and echidna.Just look at these weirdly cute little buddies.