Doomcaller is a card in the new Whispers of the Old Gods expansion, that reads "Give your C'Thun +2/+2 (wherever it is). If it's dead, shuffle it into your deck.".
This is a scenario that I will probably encounter soon: I play my C'Thun. It dies. My opponent plays C'Thun as well. I cast Entomb on it, which shuffles his C'Thun into my deck. Now I have a dead C'Thun, and another one in my deck.
If I play Doomcaller now, will it shuffle the dead one into my deck?
(similar situations occur with other cards, e.g. cards that make copies of C'Thun before it dies)