Fell Shepherd

Text:

Whenever Fell Shepherd deals combat damage to a player, you may return to your hand all creature cards that were put into your graveyard from the battlefield this turn.
, Sacrifice another creature: Target creature gets -2/-2 until end of turn.

Rulings:

• 10/17/2013 Creature cards that were put into your graveyard from any zone other than the battlefield, such as a card that was discarded, won’t return to your hand.
• 10/17/2013 Creatures dealt lethal damage at the same time Fell Shepherd deals combat damage to a player will also be returned to your hand from your graveyard. If Fell Shepherd is such a creature (perhaps because it gained trample, attacked a player, and was blocked), it will be one of the creature cards returned to your hand.
• 10/17/2013 You can choose a creature as the target of the last ability and sacrifice that same creature to activate the ability.