Good bodyguards are hard to find, mainly because they don't live long.

Veteran Bodyguard

As long as this creature is untapped, all damage that would be dealt to you by unblocked creatures is dealt to this creature instead.

30th Anniversary Edition

Masters Edition IV

As long as Veteran Bodyguard is untapped, all damage that would be dealt to you by unblocked creatures is dealt to Veteran Bodyguard instead.

Summer Magic / Edgar

Revised Edition

Unless Bodyguard is tapped, any damage done to you by unblocked creatures is done instead to Bodyguard. You may not take this damage yourself, though you can prevent it if possible. No more than one Bodyguard of your choice can take damage for you in this manner each turn.

Damage goes to the Bodyguard as long as he is untapped. This works even if he is blocking.

If a creature is blocked but Trample damage is still done to a player, this damage can't be redirected to the Bodyguard because the Bodyguard only takes damage from unblocked creatures.

If you have multiple Veteran Bodyguards, you can decide which one receives the redirected damage each time damage would be dealt to you.