Seraphic Steed

First strike, lifelink
Whenever this creature attacks while saddled, create a 3/3 white Angel creature token with flying.
Saddle 4 (Tap any number of other creatures you control with total power 4 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Forest

Get Lost

Destroy target creature, enchantment, or planeswalker. Its controller creates two Map tokens. (They're artifacts with "{1}, {T}, Sacrifice this token: Target creature you control explores. Activate only as a sorcery.")

Blossoming Sands

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

Novice Inspector

When this creature enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Axebane Ferox

Deathtouch, haste
Ward—Collect evidence 4. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player exiles cards with total mana value 4 or greater from their graveyard.)

Razorverge Thicket

This land enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {W}.

Bloated Contaminator

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

Tribute to the World Tree

Whenever a creature you control enters, draw a card if its power is 3 or greater. Otherwise, put two +1/+1 counters on it.

Colossal Rattlewurm

Colossal Rattlewurm has flash as long as you control a Desert.
Trample
{1}{G}, Exile this card from your graveyard: Search your library for a Desert card, put it onto the battlefield tapped, then shuffle.

Thalia, Guardian of Thraben

First strike
Noncreature spells cost {1} more to cast.

Polukranos, Engine of Ruin

Reach, lifelink
Whenever Polukranos or another nontoken Hydra you control dies, create a 3/3 green and white Phyrexian Hydra creature token with reach and a 3/3 green and white Phyrexian Hydra creature token with lifelink.

Polukranos Reborn

Reach
{6}{W/P}: Transform Polukranos Reborn. Activate only as a sorcery. ({W/P} can be paid with either {W} or 2 life.)

Polukranos Reborn // Polukranos, Engine of Ruin

Trostani, Three Whispers

{1}{G}: Target creature gains deathtouch until end of turn.
{G/W}: Target creature gains vigilance until end of turn.
{2}{W}: Target creature gains double strike until end of turn.

Evolving Adaptive

This creature enters with an oil counter on it.
This creature gets +1/+1 for each oil counter on it.
Whenever another creature you control enters, if that creature has greater power or toughness than this creature, put an oil counter on this creature.

Sharp-Eyed Rookie

Vigilance
Whenever a creature you control enters, if its power is greater than this creature's power or its toughness is greater than this creature's toughness, put a +1/+1 counter on this creature and investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Brushland

{T}: Add {C}.
{T}: Add {G} or {W}. This land deals 1 damage to you.

Journey On

Create X Map tokens, where X is one plus the number of opponents who control an artifact. (Then exile this card. You may cast the creature later from exile.)

Kellan, Daring Traveler

Whenever Kellan attacks, reveal the top card of your library. If it's a creature card with mana value 3 or less, put it into your hand. Otherwise, you may put it into your graveyard.