Is there a way to deal damage to a target without them knowing?


I’m playing a sneaky Poison Dusk Lizardfolk who dabbles a lot in poisons. I want to use a blowgun to inflict poisons on my targets, but I don’t want them to know they’ve been damaged. Basically, imagine someone walking down the road, and then suddenly being paralyzed. I know there’s rules for "sniping," or making a ranged attack and then hiding, but that doesn’t stop the opponent from knowing they’ve been damaged. It just stops them from finding who did it.