I'm trying to use [Verdant Succession](http://gatherer.wizards.com/Pages/Search/Default.aspx?name=%2b%5bVerdant%20Succession%5d) with only one copy of [Worldspine Wurm](http://gatherer.wizards.com/Pages/Search/Default.aspx?name=%2b%5bWorldspine%20Wurm%5d) in my deck. 

Worldspine Wurm automatically goes back in the library *when it is put into the graveyard.* Verdant Succession lets me look for a copy of a creature in my library and put it into play *when a creature dies.* So, does Worldspine Wurm end up back in my library in time for me to search for it, or no?

Also, how would this be different with a creature that says *if it would* be put into a graveyard, it gets put back into my library *instead*, like [Darksteel Colossus](http://gatherer.wizards.com/Pages/Search/Default.aspx?name=%2b%5bDarksteel%20Colossus%5d), instead of just saying *when* like Worldspine Wurm?