Otto Bagman was the brother of Ludovic Bagman. He once had a problem with a magical lawn mower, a Muggle artefact. Arthur Weasley helped him out with the problem, and was rewarded by Ludo with tickets to the 1994 Quidditch World Cup final.
"Otto" is a later German form of Audo or Odo, originally a short form of various names beginning with the Germanic element od meaning "wealth, fortune".
- Harry Potter and the Goblet of Fire (Mentioned only)