@ratkins @cstross quadcopters are probably faster and more maneuverable in general. There have been pictures emerging recently of dog-like robots being used by the AFU on the battlefield, but I think more for resupply and scouting than assassination.
Gregory's Server
@ratkins @cstross followup article: apparently AFU has deployed 30 robot dogs for recon. It does not sound like they're using them for strike, yet. Price quoted is 4K-8K Euros which is more expensive than most drones, but not order-of-magnitude more expensive.
https://english.nv.ua/nation/ukraine-deploys-over-30-british-robot-dogs-in-donbas-combat-bild-50442967.html