Well, the chick grew up into a chicken, but you’re still not sure how the egg got into that cave...

A young female dragon, not quite old enough to breed, desperately wanted to have her own egg. When she was out hunting one day, she found a nest with several small eggs in it. Without stopping to think about it, she grabbed one of the eggs and ran to the cave to hatch her little baby. She named her tiny feathered daughter She-Peep, after the peeping sound she made. She-Peep knows she's not a dragon and she figured out she is a bird of some kind, but what kind is where the issue is. With her large breast muscles and strong compact body, she feels she must be descended from a falcon or eagle. When the dragons say anything about her ability to fly not being very falcon like, she just reminds them that she wasn't trained by a falcon, but a dragon. Some of the meat eating dragons wanted to eat her at first, but when her mother came to her rescue they backed down. Now accepted by all the dragons, She-Peep helps keep the little eggs warm and lulls the hatchlings to sleep, clucking softly.