Ornate harvestmen: armored, patterned daddy longlegs of the American South and the tropics, communal, entirely harmless, and chemically eloquent, since their defence is a dab of vinegar-scented quinones rather than anything resembling a bite. The venomous-daddy-longlegs legend dies here, publicly.
They keep in groups: humid, sheltered setups with litter, bark, and gentle feeding on soft foods and prey scraps, where clusters form and persist. Long lived for the body plan, sociable by arachnid standards, and safe to a degree almost nothing else on the site matches.
Collection is trivial in range and the trade is a curiosity margin priced accordingly. The genus sells communal display and myth correction in one container, and as an ambassador animal for arachnids generally, nothing else does the job for less.