Pygmy Hippo 
Creature — Hippo
$2.09 #25805 0.53 29.6 years
Whenever this creature attacks and isn't blocked, you may have defending player activate a mana ability of each land they control and lose all unspent mana. If you do, this creature assigns no combat damage this turn and at the beginning of your next main phase this turn, you add an amount of 
equal to the amount of mana that player lost this way.
equal to the amount of mana that player lost this way.Click a line or tag to filter
Cards similar to Pygmy Hippo 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.
Drain Power76%
$3.17↑#16498↑0.80↑33.1 years↑
"Target player activates a mana ability of each land they control. Then that player loses all unspent mana and you add the mana lost this way."