Llanowar Sentinel

Creature - Elf 2/3, 2G (3)
When Llanowar Sentinel enters the battlefield, you may pay {1}{G}. If you do, search your library for a card named Llanowar Sentinel and put that card onto the battlefield. Then shuffle your library.¹
Illus. Randy Gallegos

Gatherer Card Rulings [Nov 2009]

• 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.
• 7/15/2007: Llanowar Sentinels can "chain": If you put a second Llanowar Sentinel onto the battlefield as a result of this ability, that creature's enters-the-battlefield ability triggers and allows you to search for yet another Llanowar Sentinel.

Format Legality	Legal in Vintage, Legacy, Extended, MTGO Classic Banned in Standard
Printings (2/16)	Tenth Edition (Common) Weatherlight (Common)