Battlefly Swarm

Flying
{B}: This creature gains deathtouch until end of turn.

Fume Spitter

Sacrifice this creature: Put a -1/-1 counter on target creature.

Vampire Bats

Flying (This creature can't be blocked except by creatures with flying or reach.)
{B}: This creature gets +1/+0 until end of turn. Activate no more than twice each turn.

Universal Automaton

Changeling (This card is every creature type.)

Hand of Vecna

At the beginning of combat on your turn, equipped creature or a creature you control named Vecna gets +X/+X until end of turn, where X is the number of cards in your hand.
Equip—Pay 1 life for each card in your hand.
Equip {2}

The Book of Exalted Deeds

At the beginning of your end step, if you gained 3 or more life this turn, create a 3/3 white Angel creature token with flying.
{W}{W}{W}, {T}, Exile The Book of Exalted Deeds: Put an enlightened counter on target Angel. It gains "You can't lose the game and your opponents can't win the game." Activate only as a sorcery.

Defiant Khenra

Fear of Lost Teeth

When this creature dies, it deals 1 damage to any target and you gain 1 life.

Slitherhead

Scavenge {0} ({0}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Bog Imp

Flying (This creature can't be blocked except by creatures with flying or reach.)

Unraveling Mummy

{1}{W}: Target attacking Zombie gains lifelink until end of turn.
{1}{B}: Target attacking Zombie gains deathtouch until end of turn.

Nexos

Strategic Coordinator — Basic lands you control have "{T}: Add {C}{C}. Spend this mana only on costs that contain {X}."

Simic Initiate

Graft 1 (This creature enters with a +1/+1 counter on it. Whenever another creature enters, you may move a +1/+1 counter from this creature onto it.)

Segovian Angel

Half-Kitten, Half-

Whenever you're dealt damage,
Augment {2}{W} ({2}{W}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Dreadhorde Invasion

At the beginning of your upkeep, you lose 1 life and amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)
Whenever a Zombie token you control with power 6 or greater attacks, it gains lifelink until end of turn.

The Book of Vile Darkness

At the beginning of your end step, if you lost 2 or more life this turn, create a 2/2 black Zombie creature token.
{T}, Exile The Book of Vile Darkness and artifacts you control named Eye of Vecna and Hand of Vecna: Create Vecna, a legendary 8/8 black Zombie God creature token with indestructible and all triggered abilities of the exiled cards.

Merciless Predator

At the beginning of each upkeep, if a player cast two or more spells last turn, transform this creature.

Reckless Waif

At the beginning of each upkeep, if no spells were cast last turn, transform this creature.

Reckless Waif // Merciless Predator

Festerleech

Whenever this creature deals combat damage to a player, you mill two cards.
{1}{B}: This creature gets +2/+2 until end of turn. Activate only once each turn.

Volo, Guide to Monsters

Whenever you cast a creature spell that doesn't share a creature type with a creature you control or a creature card in your graveyard, copy that spell. (A copy of a creature spell becomes a token.)

Frilled Oculus

{1}{G}: This creature gets +2/+2 until end of turn. Activate only once each turn.

Leonardo da Vinci

{3}{U}{U}: Until end of turn, Thopters you control have base power and toughness X/X, where X is the number of cards in your hand.
{2}{U}, {T}: Draw a card, then discard a card. If the discarded card was an artifact card, exile it from your graveyard. If you do, create a token that's a copy of it, except it's a 0/2 Thopter artifact creature with flying in addition to its other types.

Deathbonnet Hulk

At the beginning of your upkeep, you may exile a card from a graveyard. If a creature card was exiled this way, put a +1/+1 counter on this creature.

Deathbonnet Sprout

At the beginning of your upkeep, mill a card. Then if there are three or more creature cards in your graveyard, transform this creature. (To mill a card, put the top card of your library into your graveyard.)

Deathbonnet Sprout // Deathbonnet Hulk

Indulgent Aristocrat

Lifelink
{2}, Sacrifice a creature: Put a +1/+1 counter on each Vampire you control.

Champion of the Parish

Whenever another Human you control enters, put a +1/+1 counter on this creature.

Endless One

This creature enters with X +1/+1 counters on it.

Eye of Vecna

When Eye of Vecna enters, you draw a card and you lose 2 life.
At the beginning of your upkeep, you may pay {2}. If you do, you draw a card and you lose 2 life.