Leshrac's Sigil

Whenever an opponent casts a green spell, you may pay {B}{B}. If you do, look at that player's hand and choose a card from it. The player discards that card.
{B}{B}: Return this enchantment to its owner's hand.

Secret Lair Drop

Ice Age

o
Boo
B When any opponent successfully casts a green spell, look at that player's hand and choose a card; he or she then discards that card. Use this ability only once each time a green spell is cast.
o
Boo
B Return Leshrac's Sigil to owner's hand.