Did the grim reaper make an appearance at King Charles' Coronation? No, that's not true: the mysterious figure in a black cloak seen walking at the back of the altar was actually a staff member assisting in the coronation.
The claim appeared on TikTok (archived here) on May 9, 2023. The video shows footage taken from a Japanese news channel with the song "Death God" by Kenshi Yonezu playing in the background. The caption can be translated as:
"It's the Death God π±?! A fake that shouldn't have been recorded?!"
This is what the TikTok video looked like at the time of writing:
(Source: TikTok screenshot taken on Fri May 19 17:00:00 2023 UTC)
This claim has already been debunked by Lead Stories, and Westminster Abbey confirmed to Lead Stories via a phone interview that the mysterious figure in a black cloak was actually a verger who assists with Coronation services.