Secrets of the Dead

Whenever you cast a spell from your graveyard, draw a card.

Laboratory Drudge

At the beginning of each end step, draw a card if you've cast a spell from a graveyard or activated an ability of a card in a graveyard this turn.

River Kelpie

Whenever River Kelpie or another permanent enters from a graveyard, draw a card.
Whenever a player casts a spell from a graveyard, draw a card.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Vega, the Watcher

Flying
Whenever you cast a spell from anywhere other than your hand, draw a card.