what stinks?

I have been perplexed for two days: my bedroom smells, something stinky is hiding somewhere. Well, my room has become Cartman's another playground, when I am working, he plays in the room with me. The arrangement is perfect, except I am in deep need of a new bookshelf, to keep my books out of reach his mouth. Unfortunately Cartman has as good taste as me, on books: he eats them. Ok, tonight, after sniffing for 15 minutes inside room, BTW, Cartman was amazed by my sniffing, he stared me with his usual i-dont-believe-you-are-you-from-mars expression, but added with intense interests on me, he must think: "why mummy is using her nose so hard? I didn't smell anything?" Ok, minutes later, the stinky bomb was discovered, it was right under my nose: the tiger doll! Cartman's one of favorite toys, he went to his crate with him. It really stinks!! Cartman played with it too much, he always used his mouth to carry him, bite him or throw him. The saliva of the puppy over the couple of months made the small tiger go spoiled. Oh, don't we learn something everyday?