Vessel with Humans, Skeletons, Owls, Birds, Pumas, Seals, and Frogs by Moche https://www.rawpixel.com/image/8940480/vessel-with-humans-skeletons-owls-birds-pumas-seals-and-frogs-mocheFree Image from public domain licenseSkeletons of various reptiles: seven figures, illustrating the skeletons of an alligator, a turtle, a python, a rattlesnake… https://www.rawpixel.com/image/13954632/image-paper-cartoon-artFree Image from public domain licenseThe skeleton of a hedgehog, lizard, bat, frog, crocodile and dog. Engraving. https://www.rawpixel.com/image/14018671/the-skeleton-hedgehog-lizard-bat-frog-crocodile-and-dog-engravingFree Image from public domain licenseSkeleton and dissection of a frog, the latter showing the internal organs. Line engraving after a drawing by S. Edwards … https://www.rawpixel.com/image/13981430/image-paper-cartoon-artFree Image from public domain licenseFrogs: eleven figures showing the skeleton, circulatory system, and stages of development of the frog. Chromolithograph by… https://www.rawpixel.com/image/13981673/image-paper-cartoon-faceFree Image from public domain license