The echidna – aka the "spiny anteater" – is a mammal. But unlike almost every other mammal, baby echidnas (aka "puggles," aka "baby Max Rebos" aka "the most adorable creatures on Earth with four-headed penises") emerge into the world not from their mother's wombs, but from eggs.
This short clip from a 1974 film called Comparative Biology Lactation shows us what that looks like. It also gives us a glimpse at the puggle's adorable transparent tummy.
[Via The Kid Should See This]