Grothama, All-Devouring

Other creatures have "Whenever this creature attacks, you may have it fight Grothama, All-Devouring."
When Grothama leaves the battlefield, each player draws cards equal to the amount of damage dealt to Grothama this turn by sources they controlled.

Phantom Wurm

Phantom Wurm enters with four +1/+1 counters on it.
If damage would be dealt to Phantom Wurm, prevent that damage. Remove a +1/+1 counter from Phantom Wurm.

Havenwood Wurm

Flash (You may cast this spell any time you could cast an instant.)
Trample

Soul Swallower

Trample
Delirium — At the beginning of your upkeep, if there are four or more card types among cards in your graveyard, put three +1/+1 counters on Soul Swallower.

Pathbreaker Wurm

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Pathbreaker Wurm is paired with another creature, both creatures have trample.

Ruination Wurm

Charnelhoard Wurm

Trample
Whenever Charnelhoard Wurm deals damage to an opponent, you may return target card from your graveyard to your hand.

Sifter Wurm

Trample
When Sifter Wurm enters, scry 3, then reveal the top card of your library. You gain life equal to that card's mana value.

Impervious Greatwurm

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Indestructible

Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon, the Boundless enters, choose a creature type.
Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

Reckless Wurm

Trample
Madness {2}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Plated Slagwurm

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

Gravetiller Wurm

Trample
Morbid — Gravetiller Wurm enters with four +1/+1 counters on it if a creature died this turn.

Penumbra Wurm

Trample
When Penumbra Wurm dies, create a 6/6 black Wurm creature token with trample.

Pelakka Wurm

Trample
When Pelakka Wurm enters, you gain 7 life.
When Pelakka Wurm dies, draw a card.

Ravager Wurm

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
When Ravager Wurm enters, choose up to one —
• Ravager Wurm fights target creature you don't control.
• Destroy target land with an activated ability that isn't a mana ability.

Elderscale Wurm

Trample
When Elderscale Wurm enters, if your life total is less than 7, your life total becomes 7.
As long as you have 7 or more life, damage that would reduce your life total to less than 7 reduces it to 7 instead.

Novablast Wurm

Whenever Novablast Wurm attacks, destroy all other creatures.

Scoria Wurm

At the beginning of your upkeep, flip a coin. If you lose the flip, return Scoria Wurm to its owner's hand.

Engulfing Slagwurm

Whenever Engulfing Slagwurm blocks or becomes blocked by a creature, destroy that creature. You gain life equal to that creature's toughness.

Enlisted Wurm

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Rootbreaker Wurm

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

Voracious Wurm

Voracious Wurm enters with X +1/+1 counters on it, where X is the amount of life you've gained this turn.

Dirtcowl Wurm

Whenever an opponent plays a land, put a +1/+1 counter on Dirtcowl Wurm.

Skeletal Wurm

Roaring Slagwurm

Whenever Roaring Slagwurm attacks, tap all artifacts.

Panglacial Wurm

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

Ravaging Riftwurm

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Vanishing 2 (This creature enters with two time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
If Ravaging Riftwurm was kicked, it enters with three additional time counters on it.

Greater Sandwurm

Greater Sandwurm can't be blocked by creatures with power 2 or less.
Cycling {2} ({2}, Discard this card: Draw a card.)

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.