Yavimaya Granger

Echo {2}{G} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

The List

Urza's Legacy

Echo (During your next upkeep after this permanent comes under your control, pay its casting cost or sacrifice it.)
When Yavimaya Granger comes into play, you may search your library for a basic land card and put that land into play tapped. Shuffle your library afterward.

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.