River Weaser
From Tardis Wiki, the free Doctor Who reference
The River Weaser was a river which flowed through the town of Hamelin. (COMIC: Challenge of the Piper) In 1284, (TV: The Day of the Clown) the Pied Piper led all of the rats of Hamelin into the river by playing a tune on his magical instrument. (COMIC: Challenge of the Piper)
Behind the scenes
The river that runs through Hamelin is actually spelt "Weser", but its only known DWU mention is with the spelling "Weaser" in Challenge of the Piper.