Oracle Text

Whenever a nontoken creature you control dies, you may search your library for a card with the same name as that creature, reveal it, and put it into your hand. If you do, shuffle your library.

Card Rulings

10/4/2004 If a copy card goes to the graveyard under this effect, you get to look for another copy of the card it was copying. This is because a copy card actually takes on the name and initial characteristics of what it copies.
10/4/2004 Because the “search” requires you to find a card with certain characteristics, you don’t have to find the card if you don’t want to.
3/1/2010 If a card which is a creature only due to an effect goes to the graveyard, you can search for another copy of that card even though the card in your library won’t be a creature card.