Origin story of Zagrath the grumbling rug? Fiber is fiber, after all.
I did leave the origin of Xagthrath the Grumbling Rug and blgthrths in general rather vague.
Though I do have in the mind’s eye an image of an angry blgthrth sitting in a corner “agrily screeching and buzzing its towel like corners in a menacing fashion and the eyes, oh God why does this towel have slit like black as pitch eyes just above a similarly slit like mouth?!”
It blinks rapidly as it does a threat wobble accompanied by the buzzing, eyes sit in an angled “V” like angry eyebrows, and the mouth just opens and closes with the outraged screeches and squeaks.