From Queenpedia.com

Herefordshire-born singer with Mott The Hoople. Mott were drifitng as a pub band when David Bowie gave them All The Young Dudes and they never looked back. After Mott split, Hunter would often tour with Mick Ronson, and has issued the occasional album over the years.

Brian, Freddie & Roger appeared on his All American Alien Boy album in 1976

Brian appears on his live DVD Just Another Night

He appears on Brian's cover of Mott's All The Way From Memphis on Another World, appeared at the Freddie Tribute show, and appeared with Roger at the Mick Ronson Tribute show.