Few adventurers know of the suckering worm. They never see it, never get that far into the monstrous underground world that lives beneath us — or never return, even if they do. But the monsters know the worms. They are famous, especially amongst the betting kind. For the suckering worms run the most famous and prestigious gambling ring in all the underworld.
The game is simple. Each monster brings a piece of treasure to the worms, to prove their ability. This buys them into the games. The worms allow newcomers to join a small group of other monsters. Each of them must go out and procure a single, valuable piece of treasure and present it at the group's next meeting. Whoever presents the most valuable treasure — decided by a secret vote — wins all treasure save the cheapest in value, which the worms keep as their share. Monsters who show some ingenuity and drive — whether they win or not — are allowed to join ever more prestigious groups of gamblers. Some crafty monsters have been able to amass hordes worth several mortal fortunes simply by risking a few choice pieces.
But all is not quite as it seems, for the suckering worm does not get its name for nothing. It well knows how to lure the foolish into its gluttonous maw, whether they be human or not. Their games are not rigged, for why should they care? They have already lured those who participate in their casinos in, they need only sucker them along until it is time to devour them. If a monster loses too many times, earning the contempt of others, it is easy enough to make them disappear without creating comment. And if a group of truly heavyweight treasure-thieves assemble and present to each other a horde of the ages… well, they too might disappear, along with all their ill-gotten gains. Even if word does get around, there are always more monsters to desperate and greedy to heed the warnings of their fellows.