Have

Ichorspit Basilisk

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

Champion of Lambholt

Creatures with power less than Champion of Lambholt's power can't block creatures you control.
Whenever another creature you control enters, put a +1/+1 counter on Champion of Lambholt.

Needlethorn Drake

Infectious Bite

Target creature you control deals damage equal to its power to target creature you don't control. Each opponent gets a poison counter.

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Thirsting Roots

Choose one —
• Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Urban Daggertooth

Vigilance
Enrage — Whenever Urban Daggertooth is dealt damage, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Bloated Contaminator

Trample
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Whenever Bloated Contaminator deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Sword Coast Sailor

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, this creature can't be blocked this turn."

Triskelion

Triskelion enters with three +1/+1 counters on it.
Remove a +1/+1 counter from Triskelion: It deals 1 damage to any target.

Invisible Stalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Invisible Stalker can't be blocked.

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Corrupted Resolve

Counter target spell if its controller is poisoned.

Planar Incision

Exile target artifact or creature, then return it to the battlefield under its owner's control with a +1/+1 counter on it.

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.)

Aspirant's Ascent

Until end of turn, target creature gets +1/+3 and gains flying and toxic 1. (Players dealt combat damage by that creature also get a poison counter.)

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.

Flux Channeler

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)