Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Serrated Scorpion

When Serrated Scorpion dies, it deals 2 damage to each opponent and you gain 2 life.

Goremand

As an additional cost to cast this spell, sacrifice a creature.
Flying
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
When Goremand enters, each opponent sacrifices a creature.

Ram Through

Target creature you control deals damage equal to its power to target creature you don't control. If the creature you control has trample, excess damage is dealt to that creature's controller instead.

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

Swamp

Unlikely Aid

Target creature gets +2/+0 and gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Humble Naturalist

{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

Colossification

Enchant creature
When Colossification enters, tap enchanted creature.
Enchanted creature gets +20/+20.

Titanic Growth

Target creature gets +4/+4 until end of turn.

Honey Mammoth

When Honey Mammoth enters, you gain 4 life.

Walking Corpse

Skeleton Archer

When Skeleton Archer enters, it deals 1 damage to any target.

Ironscale Hydra

If a creature would deal combat damage to Ironscale Hydra, prevent that damage and put a +1/+1 counter on Ironscale Hydra.

Demonic Embrace

Enchant creature
Enchanted creature gets +3/+1, has flying, and is a Demon in addition to its other types.
You may cast Demonic Embrace from your graveyard by paying 3 life and discarding a card in addition to paying its other costs.

Kogla, the Titan Ape

When Kogla, the Titan Ape enters, it fights up to one target creature you don't control.
Whenever Kogla attacks, destroy target artifact or enchantment defending player controls.
{1}{G}: Return target Human you control to its owner's hand. Kogla gains indestructible until end of turn.

Almighty Brushwagg

Trample
{3}{G}: Almighty Brushwagg gets +3/+3 until end of turn.

Underworld Sentinel

Whenever Underworld Sentinel attacks, exile target creature card from your graveyard.
When Underworld Sentinel dies, put all cards exiled with it onto the battlefield.

Finishing Blow

Snarespinner

Reach
Whenever Snarespinner blocks a creature with flying, Snarespinner gets +2/+0 until end of turn.

Hyrax Tower Scout

When Hyrax Tower Scout enters, untap target creature.

Plummet

Llanowar Visionary

When Llanowar Visionary enters, draw a card.
{T}: Add {G}.

Gloom Pangolin

Grasp of Darkness

Target creature gets -4/-4 until end of turn.

Colossal Dreadmaw

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Bristling Boar

Bristling Boar can't be blocked by more than one creature.

Fetid Imp

Flying
{B}: Fetid Imp gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Yorvo, Lord of Garenbrig

Yorvo, Lord of Garenbrig enters with four +1/+1 counters on it.
Whenever another green creature you control enters, put a +1/+1 counter on Yorvo. Then if that creature's power is greater than Yorvo's power, put another +1/+1 counter on Yorvo.

Demon of Loathing

Flying, trample
Whenever Demon of Loathing deals combat damage to a player, that player sacrifices a creature of their choice.

Blood Glutton

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Forest

Lost Legion

When Lost Legion enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Treeshaker Chimera

All creatures able to block Treeshaker Chimera do so.
When Treeshaker Chimera dies, draw three cards.