The Baby That Roared

Mr. and Mrs. Deer have alwats wanted a baby, so they are delighted when a little antlered bundle appears on their doorstep one day.  But the babywon't stop roaring!  Family and friends come to help, sending Mr. and Mrs. Deer in search of what the baby needs.  But it's very particular:  everytime Mr. and Mrs. Deer return, someone is missing--and the baby is still roaring! Where did everybody go--and just what kind of baby is this?