You walk quietly through the town when suddenly PUM! a two-headed skeleton attacks you. Yes, two heads. Well, this is what several Red Dead Online players have been experiencing, after the invasion of hackers who have been making these creatures appear that attack the players.
It is not clear if they do twice as much damage by having an extra head, although we are pretty sure that you cannot skin them after beating them. Here you can appreciate how these creatures look.
There is even a post that says the same thing is happening on PS4, but it has not been verified.