wyvern: a fire-breathing dragon used in medieval heraldry; had the head of a dragon and the tail of a snake and a body with wings and two legs
dragon: a creature of Teutonic mythology; usually represented as breathing fire and having a reptilian body and sometimes wings
hepatitis b: an acute (sometimes fatal) form of viral hepatitis caused by a DNA virus that tends to persist in the blood serum and is transmitted by sexual contact or by transfusion or by ingestion of contaminated blood or other bodily fluids