Precursor Spores

{x}{w}: Sacrifice Precursor Spores. Search your library for a Non-Corporeal creature with converted mana cost X, reveal it then shuffle your library and put that card on top of your library.
"The first time I saw them I thought they were the most beautiful thing i had ever laid my eyes upon, by the next time I feared them." -Gelaxio Juran, First Year Navigator