The Platypus is one of the oddest mammals around-- they lay eggs, they don't have a stomach, but they do have a cloaca
From: https://environment.co/platypus-facts-that-are-stranger-than-fiction/ 1. They Lay Eggs 2. Scientists Thought Platypuses Were a Hoax 3. They Don’t Have a True Stomach 4. They Glow Under a Blacklight 5. Males Are Venomous 6. Their Babies Are Called Puggles 7. Adults Have No Teeth 8. They Ooze Milk 9. They Can Detect Electrical Fields 10. They Have a Cloaca