2013-07-01 : If you cast multiple Savage Summonings in succession, they’ll apply to the next creature spell you cast. That creature will enter the battlefield with that many additional +1/+1 counters on it.

2013-07-01 : Spells that would counter Savage Summoning or the relevant creature spell can still be cast. They won’t counter the spell, but any additional effects they have will happen.

2013-07-01 : You don’t choose a creature card when Savage Summoning resolves. Rather, it applies to the next creature card you cast that turn, even if you cast it at a time when you normally could cast a creature and even if you cast it from a zone other than your hand.