Expedition Lookout 

Creature — Merfolk Rogue
Defender
As long as an opponent has eight or more cards in their graveyard, this creature can attack as though it didn't have defender and it can't be blocked.
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Cards that do something similar expected a card that isn't here?
Reports become test cases the matcher is graded against before an update ships. Delvefall isn't a chatbot guessing, it compares the printed rules text of every card with plain math, and examples like yours decide which differences should count.
Deep-Sea Terror 82%
$0.18#27299
"This creature can't attack unless there are seven or more cards in your graveyard."
Vantress Gargoyle 82%
$0.32#11501
"This creature can't attack unless defending player has seven or more cards in their graveyard."
River Serpent 81%
$0.21#18500
"This creature can't attack unless there are five or more cards in your graveyard."