Yeah, Loki just went there.
After being pruned by Judge Renslayer, the God of Mischief wakes up in a desolate setting and wonders if he's died and is in Hel. He's not, but a familiar voice tells him that he will be unless "you come with us." It's Richard E. Grant, and he's suited up as the classic comic book version of Loki!
As you can see below, Marvel Studios has pulled this older Loki's costume straight off the page, and it looks amazing.
In the credits, Grant is listed as "Classic Loki," with Jack Veal playing Kid Loki and Deobia Oparei cast as Boastful Loki (when we caught a glimpse of him in the first trailer, it looked like he might be Thor).
The destroyed Avengers Tower can be seen in the background, and it seems that these pruned Lokis have all come together on this world for reasons that aren't entirely clear. Could the whole point of the TVA be to destroy or imprison every version of the trickster? If so, that makes us think another Loki is pulling the strings, but it clearly isn't going to be one played by Grant.
Then again, it's also possible someone else is gunning for Loki - Kang the Conqueror, perhaps?
Check out an amazing screenshot from Loki's unmissable post-credits scene below: