On the last page of Naruto chapter 633 Naruto, Sasuke and Sakura use summoning techniques. Who is the big frog that Naruto summoned?
UPDATE! This was confirmed in chapter 634.
Actually, based on the patterns on his body and face, I'd say that it's actually Gamakichi.
It's consistent with what this page on NarutoWiki says, although I don't know how reliable a source that is.
It is Gamakichi, as Naruto himself confirmed. In turn, Gamakichi said that his dad (Gamabunta) was busy.