48-55 cm. The biggest tern, bigger than a Common Gull. Its bill is large and all red, with a black tip, cap is black, and face, underbody white, back is grey. Legs are black. Youngs have paler bill, and patterned back. Their cap is dark, but not black.

Habitat
Scarce migratory in Hungary, on rivers, fishponds, alkaline lakes. Breeds in islands on the ground. Usually in colony.