Seasinger

When you control no Islands, sacrifice this creature. You may choose not to untap this creature during your untap step. {T}: Gain control of target creature whose controller controls an Island for as long as you control this creature and this creature remains tapped.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6o9tag6hhdpb1h7hu3xt7a.