Faris “Spout-hole” Spavin was the longest-serving Minister for Magic, from 1865-1903. Spavin was asked to leave office at the advanced age of 147 because of his eccentric behavior (Pm).
He was known for also being the most talkative Minister for Magic. Told an insensitive joke about 'a centaur, a ghost and a dwarf walk into a bar' and was nearly assassinated by an angry Centaur who kicked him (Pm).
Attended the funeral of Queen Victoria in 1901 wearing an admiral's hat and spats, at which point the Ministry suggested that he retire. He did so two years later in 1903 (Pm)
"spout-hole" = the hole on top of a whale's head from which it spouts
Presumably this refers to his well-known tendency to be long-winded.
We can guess that Spavin's love of talking earned him the nickname "Spout Hole" (mouth).