Jimmy Kimmel happens to be neighbors with Emily Blunt and John Krasinski, and he's been in an ongoing Christmas prank war with the couple since they got married a few years back. Last year, Kimmel covered their entire house in wrapping paper and littered their walk with reindeer shit, so it was incumbent upon them, according to the doctrine of mutually assured holiday destruction, to hit back even harder.
I'm not going to spoil what they did to Kimmel, but it's a halfway decent bit of schadenfreude not only for Blunt and Krasinski, but for anyone tired of his constant pranks. It cost the couple "so, so much money" to pull off, but seeing Kimmel finally get his was no doubt worth it.
That third stunt was totally staged for TV, but I don't know about the first two. I want to believe they genuinely nailed him, but if anyone would lie about a prank, it's Jimmy Kimmel.