Maybe would drop a custom Double-Action?

They should've done anything. Rehashing an old pass that's already been complete felt like a waste. I saw there was an update, redownloaded it, saw it was already done and out of disappointment uninstalled again. Poor old dead horse

Facts i was expecting a headless horseman ,or photography challenge of 4 horseman of the apocalypse with the 1st release of the Halloween Pass 1, at the very least the Halloween Pass 2 since there was a skull lantern .

no undead nightmare 2

That's a large scale investment Rcokstar would need to do. While with a random headless horseman or Halloween. Free mode events/occurrences all they apply need to do is add it into the game. Kinda of like how Snow returns every winter then by mid/late January it's gone again.

Why would the headless horseman be in a western game, even for Halloween? He's New York folklore.

Because we're in horses he's in a horse. Even in RSR2 there's literally a stranger that's from a time machine. Furthermore in both RDR2/,RDR there's horse/dig breeds that weren't based in the USA yet such as the Blackwater Nightwatch Dog and Dutch Warmblood. Another key fact is belt loops on pants. Plus some outdated weaponry such as the El Presido Cannon & Lancaster Repeater being 30 years old.

So yes on top of the anachronistic animals, weapons and a time traveler in RDR1/RDR2. There can be stuff that's out of place, Such as a legendary jaguar in Mexico from RDR. It's not that odd if the headless horseman showed up. considering we got a unicorn, 4 apocalypse horses in the game before .

They should have done an Ghost Rider

Or Both. After all in GTA there's clown Slashers abs Clone Slashers. They could do it where Ghost Rider (Horse version) spawns in New Austin/Great Plains & Scarlett Meadows while the Headless horseman spawns in Ambarino/Forest & Mountain Regions of the map