Crypt Champion

Oracle Text

Double strike

When Crypt Champion enters the battlefield, each player puts a creature card with converted mana cost 3 or less from their graveyard onto the battlefield.

When Crypt Champion enters the battlefield, sacrifice it unless R was spent to cast it.

Card Rulings

5/1/2006 The first triggered ability isn’t targeted, so the creature cards aren’t chosen until the ability resolves. Each player chooses which creature card from their own graveyard to return. If a player doesn’t have an applicable creature card, that player does nothing. If a player does have any applicable cards, that player must return one to the battlefield.
5/1/2006 If this enters the battlefield in a way other than announcing it as a spell, then the appropriate mana can’t have been paid, and you’ll have to sacrifice it.