Islandmulch {1}{2/U}, or discard a card. (You can play this card face down as a planted island land. You may turn it face up for its mulch cost.)

Desertwalk

When Tapu'Dib is turned face up and isn't tapped, and when it deals combat damage to an opponent, you may discard a card. If you do, return target creature to its owner's hand.