Foreboding Mountain

Search your library for a Mountain card and put
it onto the battlefield tapped with four slumber
counters on it, then shuffle your library. Then
that card gains "At the beginning of each end
step, if you were dealt combat damage this turn,
remove a slumber counter from this card. When
the last is removed, create a 4/4 red Dragon
creature token with flying."
Try not to disturb the dragon. Seeing that you
won't survive being disturbed by it.