Baldur's Gate 3 has a lot of reactivity, so much so that players are still finding secrets tucked away. One of these involves some major characters from Act 1 popping up again in Act 2, if you make some very specific choices.
As Reddit user piwithekiwi discovered, Dror Ragzlin can be brought back as an enemy zombie in Act 2. Others in the replies say he's not the only one and have also come across Minthara and Nere during this section of the game, depending on their choices.
In case you can't remember, Dror Ragzlin is one of the goblin leaders in Act 1. If the name sounds familiar, that's because he's the one that the goblins are forcing Volo to sing about during their party. Those who have come across him say that you have to make sure he's dead by the time you leave Act 1, so siding with the tiefling refugees rather than the goblins.
If you do this, then you'll find him as a reanimated zombie in Act 2, courtesy of Balthazar. However, you'll only come across the zombies if you follow Ketheric Thorn's orders in Act 2. In other words, you have to make the...