The vomit wambler: You (Toady) expressed concern about who ate and then vomited the food that comprised the vomit wambler. That's a question that could easily be answered by the sphere associated with it, and any deities that may have been involved in its creation. It might be fun to research the origins of these creatures (in adventure mode) before going up against them, and might even help you learn useful information about how to combat them, or where to discover artifacts that might aid you.
If the vomit wambler was associated with fertility and spring, you could easily grab any god or goddess that had that portfolio. Perhaps you hear a rumor about the creature, then start asking around. Eventually you find yourself in the temple of Ast Naefren the human goddess of motherhood and families, and the high priest tells you that the wambler is a creature of legend, supposedly created when Ast got morning sickness and ralphed in the oysters Rockefeller that her husband had prepared for her. She was so embarrassed about having ruined dinner that she buried it deep beneath the earth and pretended she had eaten it all up.
Well, that went to a silly place, but real mythology is often sillier. It'd be neat to have legends associated with the titans and forgotten beasts, especially when it becomes sort of like the story of Perseus.
And then a giant cave spider eats you.