I'm in Ghed'Ahre and have already answer 2 question. BUT the next quest…

I'm in Ghed'Ahre and have already answer 2 question. BUT the next question which is '[I CAN WALK BY DAY AND NIGHT, BUT WHEN THE MOON ARISES, SO DOES THE BEAST. WHAT AM I??]" i dont even have a clue about it!!! huhuhu
can anybody plz help me....I'm completely stuck and dont know what to do.PLZ.WHAT IS THE AWNSWER??