Nereus, Old Man of the Sea

{2}: Nereus becomes a 5/5 Serpent creature
with "This creature can't attack unless defending player controls an Island." He loses
all other types.
{3}: Nereus becomes a 6/6 Kraken creature.
He loses all other types.
{3}{u}: Nereus becomes an 8/8 Leviathan creature with islandwalk. He loses all
other types.