Frae: R. De Bruce Trotter, Galloway Gossip (1901), pp. 231-232
VERRA likely he had a richt name o’ his ain somegate, but A never kent whut it wus, an nae mair did he, an A’m thinkin his granny had nae mair notion nor her neebors. Hooever, everybuddy ca’t him “Pistie,” an it answer’t weel aneuch.
Weel, whun Pistie wus a lad aboot fourteen he saw the Sacbaun or Sedgeband, as genteel folk ca’s ’t. It maistly rows alang afore a buddy, an it means a suddent death in the hoose it stops at.
Hooever, Pistie’s yin hadna been the richt kin’, for the Sacban means the White Sack, as ye may see by its name, an Pistie’s yin wus black. Than it ran efter him instead o’ afore him; an forbye, naebuddy dee’t.
He tell’t a’ aboot it whun he gaed back tae the skule, an some boy made a sang aboot it. There’s ey some fule at a skule daft aneuch tae mak rhymes, an canna help it. An this is the “Sang”—
This entry in Galloway Gossip is the ainly citation for Sacbaun in the DSL. There are similar tales frae Argyll summarised in Jennifer Westwood & Sophia Kingshill (2009) The Lore of Scotland: A Guide to Scottish Legends, Random House, London, pp. 14-15.
Definitions frae DSL (links are tae the relevant entries).