- Born: 08/20/1987 in Vienna, Austria
- Birthname: Walter Hahn
- Height & Weight: 6'4", 297 Ib
- WWE Intercontinental Championship
- WWE/NXT United Kingdom Championship
- Progress Atlas Championship (3 times)
- Progress World Championship
Walter Hahn is an Austrian professional wrestler and trainer performing under the ring name Gunther. He is a former NXT United Kingdom Champion for which he holds the record for the longest reign at 870 days, which is the longest championship reign in WWE history since 1988. He is the leader of the Imperium stable which, alongside him, includes Ludwig Kaiser.
Hahn has appeared in a number of independent promotions around the world, predominantly wrestling mononymously as Walter (stylized in all capital letters), most notably Westside Xtreme Wrestling, becoming a three-time wXw Unified World Wrestling Champion, Pro Wrestling Guerrilla (PWG), where he is a former one-time PWG World Champion, and Progress Wrestling, where he is a former Progress Unified World Champion.
Overall, Walter is a five-time world champion in wrestling and the first Austrian to compete in WWE. After signing with WWE in early 2019, he debuted on the NXT UK brand before moving over to the primary NXT brand in 2022 where his ring name was changed to Gunther, before making his debut on the main roster.
Other Notable Achievements: Defiant Internet Championship, EWP Tag Team Championship – with Michael Kovac, Infinity Trophy, GSW Tag Team Championship – with Robert Dreissker, OTT Championship, PWF North-European Championship, PWG World Championship, wXw Unified World Wrestling Championship (3 times), wXw World Tag Team Championship (3 times) – with Robert Dreissker (1), Zack Sabre Jr. (1), and Timothy Thatcher (1), 16 Carat Gold Tournament (2010), wXw World Tag Team Tournament (2015) – with Zack Sabre Jr, World Tag Team League (2017) – with Timothy Thatcher