Prowl

Prowl is an alternative cost that appears on some Rogue creature cards. Prowl was introduced in Morningtide. You may cast a card for its prowl cost if you dealt combat damage to a player the current turn with a creature that shared a subtype with the card with Prowl. All Prowl cards have the subtype Rogue, with three Goblins and one Faerie. Prowl returned in the Zendikar Rising/Commander decks with Enigma Thief, adding Sphinx to the types.

Rulings

 * At the time you cast a spell that has prowl, you look back over the course of the turn to check if the prowl condition has been met. What matters is whether you controlled a permanent with any of the relevant creature types at the time it dealt combat damage. It doesn't matter whether you still control the permanent or if its creature types are still the same.


 * Casting a card for its prowl cost doesn't change the timing of when you can cast it. Only the cost is different.


 * Although the prowl reminder text lists specific creature types, this is done for convenience only. The prowl card's current creature types are what actually matter. For example, if a card such as Conspiracy causes a prowl spell to be an Elf, then you can pay its prowl cost rather than its mana cost only if an Elf you controlled dealt combat damage to a player that turn.


 * Prowl is optional. If you want, you can pay a spell's normal mana cost rather than pay its prowl cost.


 * Some prowl cards have enters-the-battlefield abilities or additional effects if their prowl costs were paid. You'll get them if you cast the card by paying its prowl cost rather than its normal mana cost.

Trivia

 * Prowl was featured as rules card 3 of 5 in the Morningtide set.
 * Prowl is a 6 on the Storm Scale. It wasn't particularly popular.