Dreamwinder 

Creature — Serpent
This creature can't attack unless defending player controls an Island.
{U}, Sacrifice an Island: Target land becomes an Island until end of turn.
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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.
Kukemssa Serpent 94%
$0.16#28250
"{U}, Sacrifice an Island: Target land an opponent controls becomes an Island until end of turn."
+1 more matching line
Floodchaser 100%
$0.05#28761
"This creature can't attack unless defending player controls an Island."
+1 more matching line
Manta Ray 100%
$0.14#24423
"This creature can't attack unless defending player controls an Island."
+1 more matching line
Armored Galleon 100%
$1.01#29872
"This creature can't attack unless defending player controls an Island."
Vodalian Knights 100%
#29223
"This creature can't attack unless defending player controls an Island."
+1 more matching line
Hammerhead Shark 100%
#24873
"This creature can't attack unless defending player controls an Island."
Sea Serpent 100%
#28414
"This creature can't attack unless defending player controls an Island."
+1 more matching line
Marjhan 100%
#29004
"This creature can't attack unless defending player controls an Island."
+1 more matching line
Red Cliffs Armada 100%
#30758
"This creature can't attack unless defending player controls an Island."
Dandân 100%
$9.41#21187
"This creature can't attack unless defending player controls an Island."
+1 more matching line
Deep-Sea Serpent 100%
$0.33#30165
"This creature can't attack unless defending player controls an Island."
Merchant Ship 100%
$46.42#28352
"This creature can't attack unless defending player controls an Island."
+1 more matching line
Giant Shark 100%
$0.31#25385
"This creature can't attack unless defending player controls an Island."
+1 more matching line
Ethereal Whiskergill 100%
$0.10#30473
"This creature can't attack unless defending player controls an Island."
Serpent of the Endless Sea 100%
$0.31#21050
"This creature can't attack unless defending player controls an Island."
Sealock Monster 100%
$0.08#22356
"This creature can't attack unless defending player controls an Island."
+1 more matching line