Diamond Golem

Ward {4}
Prevent all combat damage from creatures
blocking or blocked by Diamond Golem, whose
power is less that Diamond Golems toughness.
Diamond Golem's toughness is equal to your
life total.
The hardness of a diamond is part of its usefulness,
but its true value is in the light that shines through it.
-B.K.S. Iyengar