Do we have a billy goat in the house?

Recently, Savannah has started making a crazy noise when she is trying to fall asleep or wake up from a long nap. It seriously sounds like a billy goat...sometimes it sounds like a horse. Yes, I realize I am comparing the sounds my baby girl makes with those of animals, but there is no other way to describe it. She does this mostly at night when Caleb and I are also trying to go to sleep. It doesn't just last a few minutes...it last for up to 30 minutes! Although we do get a good laugh out of listening to it, sometimes we'd rather be able to go to sleep without the sound of barnyard animals in our ear.