The stink bug, or pentatomidae are a family of shield bug. They are small beetles with a shield shaped body, with widely varying colors and shapes of both their adult forms and nymphs. They get their name from their ability to secrete a foul smelling, cyanide containing liquid when threatened. This response as, well as their overall resilience, long life, and resistance to pesticides makes them relatively invulnerable to humans and predators. Some stink bugs can live for multiple years even in non-tropical climates.
Culturally, stink bugs are generally hated for their foul odor, tendency to infest human structures and trees, and their tendency to feed on crops as pests. Since they are unaffected by many pesticides they can decimate domesticated crops or garden plants. A minority of cultures consider stink bugs to be beneficial because they are sometimes predators of other beetles. People in Laos eat stink bugs.
I chose stink bugs/ shield bugs because I think they would go well with a story of trickery, infiltration, and invasion because shield bug nymphs often look nothing like their adult forms and sometimes grow up to become ferocious pests or predators. They are also attracted to heat/light, as some humans are attracted to gold. They have also invaded the mid-atlantic United States in the last decade and I have been seeing them nearly every day for years, have a very good notion of their body plan, and I hate them/would enjoy putting them into a story as an antagonist.