Treskosh, Sea Herder

Companion — Each creature card in your
starting deck is a Kraken, Leviathan, Octopus, or Serpent card. (If this card is your chosen
companion, you may put it into
your hand from outside the game for {3} any time you
could cast a sorcery.)
Other Krakens, Leviathans, Octopuses, and
Serpents you control get +1/+1 and have "{2}: This creature gains hexproof until
end of turn."