Sing up scale and down; tune could vary, the point is to sing higher and higher, then back down again
Here’s a baby birdie, hatching from her shell (hold baby ‘bird’ close)
Out pops her head, here comes her tail (touch head, wiggle bottom)
Now her legs she stretches, her wings she gives a flap (stretch legs and arms)
Then she flies and flies and flies, now what do you think of that? (lift baby up, up, up!)
Down down down down down down down ~ BOOM! (gently lower baby to floor)
And a dinosaur version (kids pretend to be inside an egg and suit actions to words):
Here's a baby dinosaur, hatching from a shell
Out pops his head, here comes his tail
Now his feet he's stomping, he gives a little roar (ROAR!)
He turns around and turns around, and sits down on the floor!
Down down down down down down down ~ BOOM!