Kohner Bros. made four superhero push puppets in the 1960's and they are  Batman, Robin, Superman and
Supergirl.  All four of these puppets are very collectible but the Superman is definitely the more common of the four.  
The Robin is the rarest of the four with Batman a close second.  The Boxed Set of Superman & Supergirl is also
quite rare.  Until recently I had never seen a supergirl push puppet with a label which lead me to believe that
supergirl was only available in the boxed set.  This turned out to be a wrong assumption as a close friend recently
acquired a supergirl with label.

Pictured Above:
1966 Superman and Supergirl Push Button Puppets - Extremely Rare
The boxed set version of superman is standing on a pink base instead of the blue base that the individual puppet is
usually seen on.  Also, the back of this box states "GET ALL 12 PUSH BUTTON PUPPET SETS IN THIS SERIES" but
this set is not listed as one of the twelve.  I can not find any box sets that advertise it's existence. Therefore this set
was possibly an after thought and I would guess it to be a very limited run.

Pictured Below:
Superman and Supergirl with labels.  Supergirl with label is quite rare and this is the only one I have seen in my 10
plus years of collecting push puppets.