When Gwen Stacy enters, exile the top card of your library. You may play that card for as long as you control this creature. {2}{U}{R}{W}: Transform Gwen Stacy. Activate only as a sorcery.

Flying, vigilance, haste Whenever you play a land from exile or cast a spell from exile, put a +1/+1 counter on Ghost-Spider. Remove two counters from Ghost-Spider: Exile the top card of your library. You may play that card this turn.