Hardened Scales

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Imp's Mischief

Change the target of target spell with a single target. You lose life equal to that spell's mana value.

Abrupt Decay

This spell can't be countered.
Destroy target nonland permanent with mana value 3 or less.

Gravecrawler

This creature can't block.
You may cast this card from your graveyard as long as you control a Zombie.

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Varolz, the Scar-Striped

Each creature card in your graveyard has scavenge. The scavenge cost is equal to its mana cost. (Exile a creature card from your graveyard and pay its mana cost: Put a number of +1/+1 counters equal to that card's power on target creature. Scavenge only as a sorcery.)
Sacrifice another creature: Regenerate Varolz.

Lotleth Troll

Trample
Discard a creature card: Put a +1/+1 counter on this creature.
{B}: Regenerate this creature.

Death's Shadow

This creature gets -X/-X, where X is your life total.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Vengevine

Haste
Whenever you cast a spell, if it's the second creature spell you cast this turn, you may return this card from your graveyard to the battlefield.