Mr Banks of Letterewe tried at great expense to drain Loch-na-Bèiste near Aultbea, in the 1850s, but failed. He also tried to poison it with quicklime. Loch-na-Bèiste is Scottish Gaelic for "loch of the beast", beast often being used for a loch monster in Ireland especially. The term loosely translates as "turtle-pig".
It has been suggested that it may be a large eel.