Autochthon Wurm

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.)
Trample

Panglacial Wurm

Trample
While you're searching your library, you may cast this card from your library.

Novablast Wurm

Whenever this creature attacks, destroy all other creatures.

Phyrexian Fleshgorger

Prototype {1}{B}{B} — 3/3 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Menace, lifelink
Ward—Pay life equal to this creature's power.

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.

Worldspine Wurm

Trample
When this creature 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.

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

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.