My first attempt at card now... as i understand it target(creature|mylibrary) will let you choose any creature? is there a way to limit it to 1? or to just have 1 random champ thrown down?
[card]
name=Thicket Elemental
kicker={1}{G}
auto=Kicker moveTo(myBattlefield) target(creature|mylibrary)
text=Kicker {1}{G} (You may pay an additional {1}{G} as you cast this spell.) When Thicket Elemental enters the battlefield, if it was kicked, you may reveal cards from the top of your library until you reveal a creature card. If you do, put that card onto the battlefield and shuffle all other cards revealed this way into your library.
mana={3}{G}{G}
type=Creature
subtype=Elemental
power=4
toughness=4
[/card]
As about now, you can't reveal cards from your library, and yes, your code will make you able to choose any creature in your library, but i don't know if there's a way to do it randomly, i think there isn't