Keyword: Threshold

Menace (This creature can’t be blocked except by two or more creatures.)
Threshold — Whenever this creature attacks, if there are seven or more cards in your graveyard, this creature gets +2/+0 until end of turn.

When this creature enters, surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Threshold — This creature can’t be blocked as long as there are seven or more cards in your graveyard.

When Kiora enters, draw two cards, then discard two cards.
Threshold — Whenever Kiora attacks, if there are seven or more cards in your graveyard, you may create Scion of the Deep, a legendary 8/8 blue Octopus creature token.

When Kiora enters, draw two cards, then discard two cards.
Threshold — Whenever Kiora attacks, if there are seven or more cards in your graveyard, you may create Scion of the Deep, a legendary 8/8 blue Octopus creature token.

Flying
Whenever this creature enters or attacks, draw a card, then discard a card.
Threshold — This creature gets +1/+1 and has deathtouch as long as there are seven or more cards in your graveyard.

Flying
When this creature enters, mill three cards. (Put the top three cards of your library into your graveyard.)
Threshold — This creature gets +2/+1 as long as there are seven or more cards in your graveyard.

When Kiora enters, draw two cards, then discard two cards.
Threshold — Whenever Kiora attacks, if there are seven or more cards in your graveyard, you may create Scion of the Deep, a legendary 8/8 blue Octopus creature token.

When Kiora enters, draw two cards, then discard two cards.
Threshold — Whenever Kiora attacks, if there are seven or more cards in your graveyard, you may create Scion of the Deep, a legendary 8/8 blue Octopus creature token.

Threshold — : Put a +1/+1 counter on Thought Shucker and draw a card. Activate only if seven or more cards are in your graveyard and only once.

Threshold — As long as seven or more cards are in your graveyard, Mind Drill Assailant gets +3/+0.
: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Shoreline Looter can’t be blocked.
Threshold — Whenever Shoreline Looter deals combat damage to a player, draw a card. Then discard a card unless seven or more cards are in your graveyard.

Menace
Threshold — When Tidecaller Mentor enters, if seven or more cards are in your graveyard, return up to one target nonland permanent to its owner’s hand.

Shoreline Looter can’t be blocked.
Threshold — Whenever Shoreline Looter deals combat damage to a player, draw a card. Then discard a card unless seven or more cards are in your graveyard.

Vigilance
Threshold — As long as seven or more cards are in your graveyard, Nightwhorl Hermit gets +1/+0 and can’t be blocked.

Persistent Marshstalker gets +1/+0 for each other Rat you control.
Threshold — Whenever you attack with one or more Rats, if seven or more cards are in your graveyard, you may pay . If you do, return Persistent Marshstalker from your graveyard to the battlefield tapped and attacking.

At the beginning of your upkeep, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Threshold — As long as seven or more cards are in your graveyard, creatures your opponents control get -1/-0.

Destroy all creatures. They can’t be regenerated.
Threshold — If seven or more cards are in your graveyard, instead destroy all creatures, then create two 1/1 white Spirit creature tokens with flying. Creatures destroyed this way can’t be regenerated.

Shroud (This creature can’t be the target of spells or abilities.)
Nim Mongoose enters the battlefield tapped.
Threshold — Nim Mongoose gets +1/+0 for each artifact you control as long as seven or more cards are in your graveyard.

Threshold — As long as seven or more cards are in your graveyard, Hunting Grounds has “Whenever an opponent casts a spell, you may put a creature card from your hand onto the battlefield.”

: Add .
Threshold — : Nantuko Monastery becomes a 4/4 green and white Insect Monk creature with first strike until end of turn. It’s still a land. Activate only if seven or more cards are in your graveyard.

At the beginning of your upkeep, you may create a 1/1 green Squirrel creature token.
Threshold — All Squirrels get +2/+2 as long as seven or more cards are in your graveyard.

Threshold — As long as seven or more cards are in your graveyard, Vigilant Sentry gets +1/+1 and has “: Target attacking or blocking creature gets +3/+3 until end of turn.”

, : Tap target creature.
Threshold — , : Tap two target creatures. Activate only if seven or more cards are in your graveyard.

Threshold — As long as seven or more cards are in your graveyard, Hunting Grounds has “Whenever an opponent casts a spell, you may put a creature card from your hand onto the battlefield.”