For this year, their King Rat is Melvyn Hayes, who played 'Gloria' Beaumont from It Ain't Half Hot Mum.
On their site they wax lyrical about the Ball where they made Melvyn the King Rat.
Where else could you see Sir Norman Wisdom receive a lifetime achievement award, sing 'Don't laugh at me' and get a standing ovation and then - half an hour later - watch Brian May, Rick Wakeman, Joe Brown, Chris Barber and Chas McDevitt perform 'Freight Train' and again have the whole room on it's feet? No one does it quite like The Grand Order of Water Rats.
Brian May, Rick Wakeman, Joe Brown and Chris Barber? Put them in the same place and surely some supernatural seismic rumbling starts and demons pour onto the earth.
There's more. For only £75 you can go to their Showbiz Quiz hosted by Jeremy Beadle.
Are there any Biblical scholars who can confirm whether the Grand Order of Water Rats are mentioned by name in the Book of Revelations?
Verily from the waters a rat did come. In the little silhouetto of a man was a King of Rats and he spake unto the people saying 'Gor blimey sergeant major', and the unholy Barber did sound his mighty trumpet, and the cloaked demon did noodle on with a keyboard solo of many years, whilst the righteous bled from their ears, until the Bearded Trickster led an inquisiton that parted the feeble minded from their coins, until all good was undone, creation itself faltered and the Smug did reign supreme over the lands of the earth and engage in much self-congratulation for their foul deeds.