Kraken Constellation

Creatures you control have hexproof and base
power and toughness 9/9.
You can't cast creature spells, play lands, and
effects can't cause you to search your library.
When you control no creatures, exile Kraken
Constellation.
When Kraken Constellation is exiled, search
your library for a Kraken, Octopus, Leviathan,
or Serpent creature, put it onto the battlefield,
then shuffle your library.