Some of the newer drones the Ukrainians are using can drop something like an RPG warhead, or multiple grenades. The smaller drones use VOG-17 grenades (used in 30mm grenade launchers) with 3D printed fins. In most situations, the grenade causes minor concussion and often survivable shrapnel wounds, if you get treated and evacuated promptly. It's particularly effective in Ukraine thanks to the lack of medical equipment and training given to the average Russian "soldier"... once injured, they do not get medical treatment or evac.