Detritivore

Detritivore's power and toughness are each equal to the number of nonbasic land cards in your opponents' graveyards.
Suspend X—{X}{3}{R}. X can't be 0. (Rather than cast this card from your hand, you may pay {X}{3}{R} and exile it with X time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)
Whenever a time counter is removed from Detritivore while it's exiled, destroy target nonbasic land.

Cantivore

Vigilance
Cantivore's power and toughness are each equal to the number of enchantment cards in all graveyards.

Necrogoyf

Necrogoyf's power is equal to the number of creature cards in all graveyards.
At the beginning of each player's upkeep, that player discards a card.
Madness {1}{B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Altar of the Goyf

Whenever a creature you control attacks alone, it gets +X/+X until end of turn, where X is the number of card types among cards in all graveyards.
Lhurgoyf creatures you control have trample.

Mortivore

Mortivore's power and toughness are each equal to the number of creature cards in all graveyards.
{B}: Regenerate Mortivore. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Lhurgoyf

Lhurgoyf's power is equal to the number of creature cards in all graveyards and its toughness is equal to that number plus 1.

Urborg Lhurgoyf

Kicker {U} and/or {B} (You may pay an additional {U} and/or {B} as you cast this spell.)
As Urborg Lhurgoyf enters, mill three cards for each time it was kicked.
Urborg Lhurgoyf's power is equal to the number of creature cards in your graveyard and its toughness is equal to that number plus 1.

Terravore

Trample
Terravore's power and toughness are each equal to the number of land cards in all graveyards.

Tarmogoyf

Tarmogoyf's power is equal to the number of card types among cards in all graveyards and its toughness is equal to that number plus 1.

Magnivore

Haste (This creature can attack and {T} as soon as it comes under your control.)
Magnivore's power and toughness are each equal to the number of sorcery cards in all graveyards.

Cognivore

Flying
Cognivore's power and toughness are each equal to the number of instant cards in all graveyards.