Goblin Spy

(15/04/2013)
If the top card of your library changes while you're casting a spell, playing a land, or activating an ability, the new top card won't be revealed until you finish doing so.

(15/04/2013)
The top card of your library isn't in your hand, so you can't suspend it, cycle it, discard it, or activate any of its activated abilities.

(15/04/2013)
When playing with the top card of your library revealed, if an effect tells you to draw several cards, reveal each one before you draw it.