Polly the Dog

Immortal(This creature can't lose abilities, and
can't be countered, targeted in any zone, sacrificed, discarded, enchanted, dealt damage,
put into another zone from the battlefield, or destroyed, and its power and toughness can't
decrease below their starting values. If this
creature would be put into a graveyard, library,
or exile from anywhere, put it into its owner's
hand instead)