Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Baru, Wurmspeaker

Wurms you control get +2/+2 and have trample.
{7}{G}, {T}: Create a 4/4 green Wurm creature token. This ability costs {X} less to activate, where X is the greatest power among Wurms you control.

Life Finds a Way

Whenever a nontoken creature you control with power 4 or greater enters, populate. (Create a token that's a copy of a creature token you control.)

Worldspine Wurm

Trample
When Worldspine Wurm dies, create three 5/5 green Wurm creature tokens with trample.
When Worldspine Wurm is put into a graveyard from anywhere, shuffle it into its owner's library.

Argothian Wurm

Trample
When Argothian Wurm enters, any player may sacrifice a land of their choice. If a player does, put Argothian Wurm on top of its owner's library.

Rhonas the Indomitable

Deathtouch, indestructible
Rhonas the Indomitable can't attack or block unless you control another creature with power 4 or greater.
{2}{G}: Another target creature gets +2/+0 and gains trample until end of turn.

Traverse the Outlands

Search your library for up to X basic land cards, where X is the greatest power among creatures you control. Put those cards onto the battlefield tapped, then shuffle.

Witherscale Wurm

Whenever Witherscale Wurm blocks or becomes blocked by a creature, that creature gains wither until end of turn. (It deals damage to creatures in the form of -1/-1 counters.)
Whenever Witherscale Wurm deals damage to an opponent, remove all -1/-1 counters from it.

The Skullspore Nexus

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
Whenever one or more nontoken creatures you control die, create a green Fungus Dinosaur creature token with base power and toughness each equal to the total power of those creatures.
{2}, {T}: Double target creature's power until end of turn.

Tempting Wurm

When Tempting Wurm enters, each opponent may put any number of artifact, creature, enchantment, and/or land cards from their hand onto the battlefield.

Sandwurm Convergence

Creatures with flying can't attack you or planeswalkers you control.
At the beginning of your end step, create a 5/5 green Wurm creature token.

Roar of Challenge

All creatures able to block target creature this turn do so.
Ferocious — That creature gains indestructible until end of turn if you control a creature with power 4 or greater.

Scale Up

Until end of turn, target creature you control becomes a green Wurm with base power and toughness 6/4.
Overload {4}{G}{G} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Apex Observatory

Apex Observatory enters tapped. As it enters, choose a card type shared among two exiled cards used to craft it.
{T}: The next spell you cast this turn of the chosen type can be cast without paying its mana cost.

Eye of Ojer Taq

{T}: Add one mana of any color.
Craft with two that share a card type {6} ({6}, Exile this artifact, Exile the two from among other permanents you control and/or cards from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Eye of Ojer Taq // Apex Observatory

Inscription of Abundance

Kicker {2}{G}
Choose one. If this spell was kicked, choose any number instead.
• Put two +1/+1 counters on target creature.
• Target player gains X life, where X is the greatest power among creatures they control.
• Target creature you control fights target creature you don't control.

Roaring Slagwurm

Whenever Roaring Slagwurm attacks, tap all artifacts.

Bellowing Tanglewurm

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Other green creatures you control have intimidate.

Goreclaw, Terror of Qal Sisma

Creature spells you cast with power 4 or greater cost {2} less to cast.
Whenever Goreclaw, Terror of Qal Sisma attacks, each creature you control with power 4 or greater gets +1/+1 and gains trample until end of turn.

Garruk, Primal Hunter

+1: Create a 3/3 green Beast creature token.
−3: Draw cards equal to the greatest power among creatures you control.
−6: Create a 6/6 green Wurm creature token for each land you control.

Winds of Qal Sisma

Prevent all combat damage that would be dealt this turn.
Ferocious — If you control a creature with power 4 or greater, instead prevent all combat damage that would be dealt this turn by creatures your opponents control.

Emergent Woodwurm

Backup 3 (When this creature enters, put three +1/+1 counters on target creature. If that's another creature, it gains the following ability until end of turn.)
Whenever this creature attacks, look at the top X cards of your library, where X is its power. You may put a permanent card with mana value X or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Whisperer of the Wilds

{T}: Add {G}.
Ferocious — {T}: Add {G}{G}. Activate only if you control a creature with power 4 or greater.

Rishkar's Expertise

Draw cards equal to the greatest power among creatures you control.
You may cast a spell with mana value 5 or less from your hand without paying its mana cost.

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

Panglacial Wurm

Trample
While you're searching your library, you may cast Panglacial Wurm from your library.

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Wurmcoil Engine

Deathtouch, lifelink
When Wurmcoil Engine dies, create a 3/3 colorless Phyrexian Wurm artifact creature token with deathtouch and a 3/3 colorless Phyrexian Wurm artifact creature token with lifelink.

Defiler of Vigor

Trample
As an additional cost to cast green permanent spells, you may pay 2 life. Those spells cost {G} less to cast if you paid life this way. This effect reduces only the amount of green mana you pay.
Whenever you cast a green permanent spell, put a +1/+1 counter on each creature you control.

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

The First Iroan Games

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I — Create a 1/1 white Human Soldier creature token.
II — Put three +1/+1 counters on target creature you control.
III — If you control a creature with power 4 or greater, draw two cards.
IV — Create a Gold token. (It's an artifact with "Sacrifice this artifact: Add one mana of any color.")