Kederekt Parasite 
Creature — Horror
Whenever an opponent draws a card, if you control a red permanent, you may have this creature deal 1 damage to that player.
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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.
Fate Unraveler 85%
$3.12#1693
"Whenever an opponent draws a card, this creature deals 1 damage to that player."
Nekusar, the Mindrazer 80%
$3.76#3676
"Whenever an opponent draws a card, this card deals 1 damage to that player."