Professor Saul Croaker was an Unspeakable for the Department of Mysteries, working in this position his entire life, including the summer of 1994. Croaker attended the 1994 Quidditch World Cup final, either attending with or meeting fellow Unspeakable Broderick Bode. Croaker was among the Ministry employees that passed by the Weasley family's campsite.
A "Croaker" is someone who habitually predicts evil; it has that sense because croaking is a noise made by crows and ravens, who are considered death omens, as they are carrion eaters.
Notes and references