Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Tetsuko Umezawa, Fugitive

Creatures you control with power or toughness 1 or less can't be blocked.

Tandem Lookout

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Tandem Lookout is paired with another creature, each of those creatures has "Whenever this creature deals damage to an opponent, draw a card."

Gateway Sneak

Whenever a Gate you control enters, this creature can't be blocked this turn.
Whenever this creature deals combat damage to a player, draw a card.

Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Divination

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Drawn from Dreams

Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in a random order.

Surrakar Spellblade

Whenever you cast an instant or sorcery spell, you may put a charge counter on this creature.
Whenever this creature deals combat damage to a player, you may draw X cards, where X is the number of charge counters on it.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Neurok Commando

Shroud (This creature can't be the target of spells or abilities.)
Whenever this creature deals combat damage to a player, you may draw a card.