Swimmer in Nightmares 
Creature — Nightmare Merfolk
$0.22 #28966 0.06 6.7 years
This creature gets +3/+0 as long as there are ten or more cards in a single graveyard.
This creature can't be blocked as long as you control an Ashiok planeswalker.
Click a line or tag to filter
Cards similar to Swimmer in Nightmares 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.
Jace's Phantasm76%
$0.26↑#8019↑0.0014.3 years↑
"This creature gets +4/+4 as long as an opponent has ten or more cards in their graveyard."
Jace's Sentinel74%
$0.13↓#234250.009.1 years↑
"As long as you control a Jace planeswalker, this creature gets +1/+0 and can't be blocked."
Blackbloom Rogue // Blackbloom Bog70%
$0.14↓#8828↑0.106.1 years
"This creature gets +3/+0 as long as an opponent has eight or more cards in their graveyard."
Devourer of Memory70%
$0.19↓#22412↑0.066.7 years
"Whenever one or more cards are put into your graveyard from your library, this creature gets +1/+1 until end of turn and can't be blocked this turn."