Seasinger 
Creature — Merfolk
$0.27 #21396 0.44 32.0 years
When you control no Islands, sacrifice this creature.
You may choose not to untap this creature during your untap step.
: Gain control of target creature whose controller controls an Island for as long as you control this creature and this creature remains tapped.Click a line or tag to filter
Cards similar to Seasinger 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.
Sea Serpent92%
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"When you control no Islands, sacrifice this creature."
+1 more matching line
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"When you control no Islands, sacrifice this creature."
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"When you control no Islands, sacrifice this creature."
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Dandân90%
$1.34↑#217840.33↓32.8 years
"When you control no Islands, sacrifice this creature."
+1 more matching line
Vodalian Knights89%
$1.01↑#29928↓0.07↓32.0 years
"When you control no Islands, sacrifice this creature."
+1 more matching line
Pirate Ship88%
$0.45↑#219990.16↓33.2 years↑
"When you control no Islands, sacrifice this creature."
+1 more matching line
Skeleton Ship88%
$6.31↑#210560.27↓31.4 years
"When you control no Islands, sacrifice this card."
Merchant Ship88%
$42.56↑#28771↓0.12↓32.8 years
"When you control no Islands, sacrifice this creature."
+1 more matching line
Island Fish Jasconius87%
$0.32↑#26903↓0.00↓32.8 years
"When you control no Islands, sacrifice this creature."
+2 more matching lines
Giant Shark86%
$0.31↑#26007↓0.00↓32.2 years
"When you control no Islands, sacrifice this creature."
+1 more matching line
Kukemssa Serpent86%
$0.11↓#28948↓0.00↓30.0 years↓
"When you control no Islands, sacrifice this creature."
+1 more matching line
Gorilla Pack85%
$0.18↓#27032↓0.00↓31.4 years
"When you control no Forests, sacrifice this creature."
Bog Serpent84%
$0.10↓#30754↓0.00↓19.7 years↓
"When you control no Swamps, sacrifice this creature."
Barbarian Outcast84%
$0.05↓#31388↓0.00↓24.7 years↓
"When you control no Swamps, sacrifice this creature."
Marjhan84%
$0.58↑#29633↓0.06↓31.1 years
"When you control no Islands, sacrifice this creature."
+2 more matching lines
Ronom Serpent80%
$0.08↓#28004↓0.00↓20.2 years↓
"When you control no snow lands, sacrifice this creature."
Serendib Djinn78%
$151.56↑#28315↓0.00↓32.8 years
"When you control no lands, sacrifice this creature."
Rubinia Soulsinger78%
$0.37↑#194260.63↑32.4 years
": Gain control of target creature for as long as you control this card and this card remains tapped."
: Gain control of target creature for as long as you control this card and this card remains tapped."+1 more matching line
Old Man of the Sea74%
$240.67↑#26094↓0.3832.8 years
"You may choose not to untap this creature during your untap step."
+1 more matching line
Emperor Crocodile74%
$0.10↓#29120↓0.4027.4 years↓
"When you control no other creatures, sacrifice this creature."