BTVS: TALES OF THE SLAYERS
The Buffybot was an identical robot replica of the real Buffy Summers. After Buffy's death, the Buffybot is used for patrolling to ensure the Underworld does not discover the Slayer's death -- if demons think Buffy is alive, they are less likely to strike, out of fear. Unfortunately, one vampire discovers the secret when fighting with her and brings a demon biker gang to Sunnydale to tear the place apart. The demons destroy the Buffybot by tearing her limb from limb. Before "dying", the Buffybot reveals to Dawn that the real Buffy has returned. The Buffybot has not since been repaired.