Convention Maro

Whenever you cast a spell that [CHOICE A], create a green Elemental creature token named Maro with "This creature's power and toughness are each equal to the number of [CHOICE B]." — As you create your deck, choose an [A] and a [B] — • [A1] "is an Elemental" | [A2] "has a watermark or landscape orientation" | [A3]

"targets a creature you control" • [B1] "cards in your hand" | [B2] "card types among cards in your graveyard" | [B3] "artists among nonland, nontoken permanents you control"

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6om457g3bvpb1h5nqz26wf.