Platypus
The platypus is a weirdo that was thought to be a made up creature for a large chunk of history. This definitely totally real egg laying mammal has retractable spurs in each back leg that produce enough venom to kill a large dog. Interestingly, only the male platypus has this defense mechanism which has lead some people to believe that it’s used less as protection against other animals and more to determine which male platypus will have the privilege of mating with a sweet lady platypus.
Source: https://www.pinterest.fr/pin/301881981256742560/