The ahemophagous (like that?) bat drags in a tiny pumpkin, and heaves it with difficulty till it's under the last unoccupied barstool. Then, having flitted up onto the creased magenta velour seat via a quick dip into Rap's drink, they order yet another Irish coffee, and ask for a small paring knife. Looking down the bar, with a whipped cream moutache making them look rather likeca negative of Snidely Whiplash or Boris Badenov (prosopagnisia again) they ask Are ye planning on being Santa for Halloween, then, lassie?
The Irish coffee having disappeared while piping hot, as explained in The Ling Spoon, the bat frops the paring knife carefully point down, flits quickly via Sev's drink to their little pumpkin, and starts planning, devilishly.
In the lomg run, there is a little pumpkin jack-o-lantern on the windwsill (not the one towards the beach, the one to where it's always after dark), lit by a third of a birthday cake candle. It has a welcoming if lopsided grin with snaggly teeth, stellate eyes bursting with laugh lines, and a debonair beret basque.
Now, what costume, hmmmm....

But yeah, Secret Santa, the bat adds over their shoulder, flitting back onto the barstool and ordering s decaf Irish mocha. Didna mean to discourage the idea...