Incremental Blight

Put a -1/-1 counter on target creature, two -1/-1 counters on another target creature, and three -1/-1 counters on a third target creature.

Choking Fumes

Put a -1/-1 counter on each attacking creature.

Contagion Clasp

When this artifact enters, put a -1/-1 counter on target creature.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Contagion Engine

When this artifact enters, put a -1/-1 counter on each creature target player controls.
{4}, {T}: Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Wickerbough Elder

This creature enters with a -1/-1 counter on it.
{G}, Remove a -1/-1 counter from this creature: Destroy target artifact or enchantment.

Blighted Blackthorn

Whenever this creature enters or attacks, you may blight 2. If you do, you draw a card and lose 1 life. (To blight 2, put two -1/-1 counters on a creature you control.)

Evolution Sage

Landfall — Whenever a land you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Deity of Scars

Trample
This creature enters with two -1/-1 counters on it.
{B/G}, Remove a -1/-1 counter from this creature: Regenerate this creature.