Scion of Shifting Snows

Unless you've spent {s} this turn, Scion of
Shifting Snows isn't a creature.
Flying, protection from snow and from instants
Whenever Scion of Shifting Snows enters the battlefield or attacks, you may either switch its
power and toughness or put an ice counter on
target permanent. That permanent is snow in addition to its other types for as long as it has
an ice counter on it.