Shoreline Scout is a uncommon Creature — Merfolk Scout card from Jumpstart: Historic Horizons (J21), collector number 12.
When Shoreline Scout enters the battlefield, you may exile a Merfolk card or a land card from your hand. If you do, conjure a card named Tropical Island into your hand. As long as another Merfolk or an Island entered the battlefield under your control this turn, Shoreline Scout gets +1/+0.