Ofelia keeps crawling in the mud until she finds the enormous toad.
He isn't a very nice toad either. He grabs her face with his giant tongue and gives her a nice big burp, trying to scare her.
But Ofelia doesn't back down. She tricks him into eating a bug (which has the stones cunningly. The toad gulfs them down and then vomits out a mass of bugs and stomach fluid—yeah, it's nasty—before deflating in a pile of toad skin.
Ofelia grabs the key from the mess, but when she makes it back outside it is nearly dark and her beautiful dress has fallen to the ground as is completely covered in mud. It starts to rain.