Boreal Outrider 
Snow Creature — Elf Warrior
$0.26 #13142 0.47 5.7 years
Whenever you cast a creature spell, if 
of any of that spell's colors was spent to cast it, that creature enters with an additional +1/+1 counter on it. ( is mana from a snow source.)
of any of that spell's colors was spent to cast it, that creature enters with an additional +1/+1 counter on it. ( is mana from a snow source.)Click a line or tag to filter
Cards similar to Boreal Outrider 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.
Wildgrowth Archaic77%
$0.27↑#116520.12↓0.5 years↓
"Whenever you cast a creature spell, that creature enters with X additional +1/+1 counters on it, where X is the number of colors of mana spent to cast it."
Ultros, Obnoxious Octopus70%
$0.21↓#146620.36↓1.4 years↓
"Whenever you cast a noncreature spell, if at least eight mana was spent to cast it, put eight +1/+1 counters on this card."
Communal Brewing70%
$0.93↑#3663↑0.26↓2.2 years↓
"Whenever you cast a creature spell, that creature enters with X additional +1/+1 counters on it, where X is the number of ingredient counters on this enchantment."