Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Ichorclaw Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Ichorclaw Myr becomes blocked, it gets +2/+2 until end of turn.

Silver Myr

Mistblade Shinobi

Ninjutsu {U} ({U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Mistblade Shinobi deals combat damage to a player, you may return target creature that player controls to its owner's hand.

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Blighted Agent can't be blocked.

Jhessian Thief

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever Jhessian Thief deals combat damage to a player, draw a card.

Looter il-Kor

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Looter il-Kor deals damage to an opponent, draw a card, then discard a card.

Scroll Thief

Whenever Scroll Thief deals combat damage to a player, draw a card.

Tetsuko Umezawa, Fugitive

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