The goldenrod crab spiders: flower ambushers that change colour between white and yellow to match their perch, then take pollinators several times their size with front legs built like calipers.
The keeping is a flower with a tenant: a planted or artificial bloom, flying prey, gentle conditions, and light, since the colour change follows what the spider sits on and takes days to run. Venom is unremarkable; the ambush is the display and it happens in daylight.
The lifespan is a single season, which frames every purchase as a summer subscription, and supply is seasonal collection at the price abundance enforces. The genus trades as a windowsill project: modest, charming, temporary, and one of the few spiders whose entire hunting life can be watched in full sun.