Darkstar Augur

Offspring {B} (You may pay an additional {B} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Flying
At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.

Mister Negative

Vigilance, lifelink
Darkforce Inversion — When Mister Negative enters, you may exchange life totals with target opponent. If you lost life this way, draw that many cards.

Parker Luck

At the beginning of your end step, two target players each reveal the top card of their library. They each lose life equal to the mana value of the card revealed by the other player. Then they each put the card they revealed into their hand.

Caustic Bronco

Whenever this creature attacks, reveal the top card of your library and put it into your hand. You lose life equal to that card's mana value if this creature isn't saddled. Otherwise, each opponent loses that much life.
Saddle 3 (Tap any number of other creatures you control with total power 3 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Dark Confidant

At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.