Answer:
My keepers feed me colored balls. With sticks they store on my den walls. Sometimes I store them in my pouch. Sometimes deep in my belly; ouch!
I stand in one place yet fill the whole room. I can be filled with molten rock and come in every hue. What am I?
What has legs but doesn't walk?
Without a bridle or a saddle across a thing I ride a-straddle. And those I ride by help of me though almost blind are made to see.
I produce wool and spit a lot
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.