What is a large black bird with loud harsh call called?

Magpies are common black and white birds that are very large. Depending on where you observed it, and your idea of large, the above may well be correct. A magpie is a bit larger than a crow, with a much longer tail. They are found in northern temperate climates. Other possibilities would be wood storks, ibis, loggerhead or northern shrikes, osprey and several others. That's in the US. Perhaps birders from elsewhere in the world will have something to add.