Unexpected Fangs

Put a +1/+1 counter and a lifelink counter on target creature.

Champion of the Perished

Whenever another Zombie you control enters, put a +1/+1 counter on Champion of the Perished.

Hancock, Ghoulish Mayor

Each other creature you control that's a Zombie or Mutant gets +X/+X, where X is the number of counters on Hancock, Ghoulish Mayor.
Undying (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.)

Lord of the Accursed

Other Zombies you control get +1/+1.
{1}{B}, {T}: All Zombies gain menace until end of turn.

Feast on the Fallen

At the beginning of each upkeep, if an opponent lost life last turn, put a +1/+1 counter on target creature you control.

Unspeakable Symbol

Pay 3 life: Put a +1/+1 counter on target creature.

Astarion's Thirst

Exile target creature. Put X +1/+1 counters on a commander creature you control, where X is the power of the creature exiled this way.

Feral Ghoul

Menace
Whenever another creature you control dies, put a +1/+1 counter on Feral Ghoul.
When Feral Ghoul dies, each opponent gets a number of rad counters equal to its power.

Fain, the Broker

{T}, Sacrifice a creature: Put two +1/+1 counters on target creature.
{T}, Remove a counter from a creature you control: Create a Treasure token.
{T}, Sacrifice an artifact: Create a 2/1 white and black Inkling creature token with flying.
{3}{B}: Untap Fain, the Broker.