There is a species of frog I read about that, because of a higher
sugar content in its cells, formed ice
crystals with more sides that humans. Because there were more sides the
points were less pronounced and the crystals for the most part did not damage the frogs cells. The frog could be completely frozen for an period and be
thawed and still
live.
I am not sure how long the frog could freeze for though. I'm sure if it was frozen for too long when it thawed it would not resume living.