Chord of Calling [Ravnica: City of Guilds]

Description

Set:	Ravnica: City of Guilds
Type:	Instant
Rarity:	Rare
Cost:	{X}{G}{G}{G}

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Search your library for a creature card with converted mana cost X or less and put it onto the battlefield. Then shuffle your library.