No creation myths here, boys and girls. Bumba Din is onomatopoeia at its worst. Or at least that's the only description we can offer without fear of legal threats. She's a creature of rust, metal, and ponderous bulk. There's some unidentifiable goo in there someplace too, it's pretty nasty.
"Bumba. Bumba Butt. She's one o' da Butt sisters."