Whenever Sun Titan enters the battlefield or attacks, you may return target permanent card with converted mana cost 3 or less from your graveyard to the battlefield.
8/15/2010 A permanent card is an artifact, creature, enchantment, land, or planeswalker card.
8/15/2010 The converted mana cost of a card in your graveyard is determined solely by the mana symbols printed in its upper right corner. The converted mana cost is the total amount of mana in that cost, regardless of color. For example, a card with mana cost has converted mana cost 5.
8/15/2010 If the mana cost of a card in your graveyard includes , X is considered to be 0.
8/15/2010 If a card in your graveyard has no mana symbols in its upper right corner (because it’s a land card, for example), its converted mana cost is 0.