[rsifytpw] Mosquito assassin

The mosquito needs to avoid getting slapped while feasting, so (I think) it injects a painkiller immediately after piercing the skin.

Adapt this technique to an assassin's weapon, injecting poison but needing to avoid getting caught in the act -- make a getaway before the victim notices the needle prick.

Certainly peacetime medical uses for people who don't like getting shots.