Saboteur are sneaky ones: They can cloak, which makes them invisible, but not so much. In cloak, if he sees sentry, lifeline, teleporters, stonehedges, he will throw an sapper into them. When building is sapped, it starts to fastly drain health, upon reaching 0 HP it explodes. You can remove sapper by hitting it with wrench, or simply removing it. When there is no buildings and he is cloaked, he will sneak to player then uncloaking and firing him at dual silenced pistols. He may plant an mine.