A couple of things about this IotM:
Ghost of Crimbo Cheer doesn't appear to be showing up under "stat gain" familiars in the mafia picker. (at least, not for me)
Enthroned Ghost of Crimbo Cheer: does small (3-5-ish) spooky damage on random rounds; haven't used it enough to nail down activation rate (and probably won't any time soon), but seems somewhere >20% and <50%. Also the listed +3 stats/fight enchantment on the throne/bjorn.
Snow Zones: Seems to make the first 4 zones of the day you adventure in snowy. Snow persists even if you switch familiars. All cold damage in a snow zone is multiplied by 1.5. This includes both spell damage and melee damage. The multiplier applies to base damage (e.g., of cold-aligned spells) as well as bonus damage. (e.g., sleaze-aligned weapon of the pastalord did 230230 phys + 230230 stench; cold-aligned WoP did 229094 phys + 343641 cold; physical attack with only an old ball and chain for elemental damage (+100 cold damage) did +150 cold damage in a snow zone) The multiplier won't help align saucegeyser (saucegeyser against an unaligned monster with +112 hot spell damage and +110 cold spell damage in a snowy zone was still hot), so need to be careful about showing multiplied modifiers, or it might lead to some confusion. Possibly just track which zones are snowy ("in the snow"), and leave the rest to the player/script writer.
Familiar equipment: Mafia's current default behavior is to equip the best available familiar gear when you change familiars, unless the familiar you were changing off of wasn't using familiar equipment, in which case it leaves the new familiar naked if it was naked to begin with. If I'm using a hookah/astral pet sweater/tall grass equipment for all my familiars, that results in my often having a naked familiar after switching away from the ghosts, since they can't be equipped. Indeed, it can result in my using naked familiars for many turns if I don't notice. I'm requesting that this change.
I'd prefer if mafia always equipped naked familiars on changing (I'm not entirely sure of the historical reasons for the current behavior, though, maybe there's a good reason it doesn't do that, but I have no use cases where I want mafia to leave my familiars naked, if I have equipment they can use somewhere), but at least, it should probably treat ghosts as if they were equipped when changing off of them.