Infectious Inquiry

You draw two cards and you lose 2 life. Each opponent gets a poison counter.

Sheoldred's Headcleaver

Menace
Toxic 2 (Players dealt combat damage by this creature also get two poison counters.)

Dune Mover

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Dune Mover enters, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

Basilica Shepherd

Flying
When Basilica Shepherd enters, create two 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This creature can't block." (Players dealt combat damage by them also get a poison counter.)

Crawling Chorus

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Crawling Chorus dies, create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This creature can't block."

Anoint with Affliction

Exile target creature if it has mana value 3 or less.
Corrupted — Exile that creature instead if its controller has three or more poison counters.

Scoured Barrens

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {B}.

Compleat Devotion

Target creature you control gets +2/+2 until end of turn. If that creature has toxic, draw a card.

Charge of the Mites

Choose one —
• Charge of the Mites deals damage equal to the number of creatures you control to target creature or planeswalker.
• Create two 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This creature can't block." (Players dealt combat damage by them also get a poison counter.)

Pestilent Syphoner

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Blightbelly Rat

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Blightbelly Rat dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Plains

Swamp

Flensing Raptor

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Flensing Raptor enters, another target creature you control with toxic gets +1/+1 and gains flying until end of turn.

Vraska's Fall

Each opponent sacrifices a creature or planeswalker of their choice and gets a poison counter.