Spookin is my plugin submission for a Plugin Jam hosted by CodedRed(more info here), it adds few items and mechanic that are themed around halloween season, brief list of all features is given below;

Dependencies:
ProtocolLib
Resource Pack

Optionally place this datapack in your world/datapacks folder for some funny advancements
Datapack

Curses
Curse yourself or other players with 6 different curses
All curses consists of 2 items, you need to throw these 2 items with a enchanted book having enchants like Binding or Vanishing and a dagger imbued with player which you want curse in a water filled cauldron
If the ritual is successful, particles will spawn and you will be given the hex book that is attached to the imbued player
Tossing the book in soul campfire block will apply the curse to player
Curse can be removed by either dyeing or drinking milk
Sleep: prevents you from sleeping [Phantom Membrane & Spider Eye]
Sickness: mis-indicates the health bar [GhastTear & GunPowder]
Starvation: mis-indicates the hunger bar [RottenFlesh & GunPowder]
Fake Fear: makes you see mobs that aren't real [Bone & Blaze Powder]
Animal Fear: animals will run away from you [RottenFlesh & Redstone dust]
SlipperyHands: randomly drops item you are holding on ground [Honey Bottle & Slimeball]
Lost Tounge: turns anything you type in chat gibbresh [Honey Comb & Slimeball]

Monster Box
Monster box are special spawners which can be found randomly in a cave, if player(in survival) goes too close to this box various mobs spawns and the box breaks, these mobs have a chance to drop a monster box itself


ScareCrow
Scarcrow can be obtained through wandering traders(due to a bug it dosn't work use /spookin give player scarecrow command instead), they repel all undead mobs like zombie,husk,skeleton,zombiefied piglin etc.

Spookier Mobs
Adds some changes to few hostile mobs like,
Creepers have a chance to explode on killed
Zombie,Husk,Drowned have a chance to spawn with baby varients riding them
Enderman have a chance to spawn holding tnt, once they get agro on player they will place and ignite the tnt nearby player
Witches have chance to drop candies
Wandering Trader will spawn with a witch hat, they also have a trade for it

Trick or Treat Basket
Adds a basket which on breaking as a block dispenses all its contents like a dispenser facing up
Wandering trader will offer few surprise basket trades
Baskets are craftable too with orange_dye,chest and paper

Candies
Uncraftable treats, only obtainable through witch drops and by breaking wandering trade's trick or treat baskets
on eating gives various effects to player

Jack O' Launcher
Features two items launcher ammo and Jack O' Launcher itself,
Ammo can be crafted by combining various items with a jack o lantern in crafting table, each item gives unique effect to the resulting ammo
some require gun powder as a complementary ingredient and some don't
here is the list of ammo ingredients:
Gunpowder(max 8): increases the yeild/power of explosion
Wool(max 1): dosn't destroy blocks due to explosion but damages entity
Firecharge(max 1): the explosion will also set blocks on fire
BoneBlock(max 1): applies a bone meal effect 4 by 4 area of impact
FireworkRocket(max 1): projectile will no longer have gravity, makes the appropriate firework effect on end or impact
Enderpearl(max 1): teleports the shooter on projectile impact
Splash Potion(max 1): breaks the splash potion and applies effect to nearby entities on projectile explodes
Lingering Potion(max 1): breaks the potion and leaves a lingering effect behind after explosion
Gold nugget(max 3): depending on nuggets supplied it will apply fortune effect on all destroyed blocks
feather(max 1): applies silk touch on destroyed blocks




Commands:
/ spookin give [player-name] [item] [count]: gives player specified item
/ spookin searchbox: locates a monster nearby player
/ sookin givebook [name]: gives player specified curse book
/ spookin reload: reloads config

Important Note: this plugin was made in hurry for competition so its not customizable at all and also might contain bugs, do NOT use in production servers, do not expect any support from me for future versions