There is a 1/10 chance to encounter the Pumpkillager when harvesting a pumpkin block. The pumpkin block has to be surrounded with empty spaces in the directions NESW, and above it. This is to prevent him from spawning where he shouldn't (e.g. custom pumpkin buildings). The mod adds a chance for a pumpkin to generate whenever a pig spawns, this will sprinkle some extra pumpkins around the world. This increases the chance of coming across the Pumpkillager naturally.

Taking the questbook from the Pumpkillager will allow you to start the quest. Use multi-block rituals and conversations to advance. The boss fight will require you to be prepared, grab your best armour and a shield! Possibly some potions. Don't worry, you'll know when the fight will happen.

1.0.0-better_maces-mod-1.21.9.jar adaptiveview-2.4.1+1.21.9.jar addonslib-fabric-1.21.6-1.5.jar advancednetherite-fabric-2.3.1-1.21.10.jar AE_F21_1.2.1.jar animated-mojang-logo-1.2-1.21.9-10.jar anvianslib-fabric-1.21.10-1.4.jar appleskin-fabric-mc1.21.9-3.0.7.jar architectury-18.0.8-fabric.jar AsyncParticles-Lite-0.7.1-alpha+1.21.10.jar autofish-1.1.2.jar AutoJumpFix-1.0.3+1.21.10.jar Auto_Elytra_F21.10.jar AxesAreWeapons-1.9.4-fabric-1.21.5.jar badpackets-fabric-0.10.2.jar banhammer-0.15.1+1.21.10.jar better-babies-1.8.2.jar better-boat-movement-2.5.1-1.21.9+fabric.jar better-sniffers-4.5.jar better-snowy-biome-v2.5.1.jar BetterAddServer-1.21.6-fabric-1.3.0.jar BetterAnimationsCollection-v21.10.0+mc1.21.10-Fabric.jar BetterCapes-1.4.1+1.21.10.jar bettercombat-fabric-3.0.0+1.21.10.jar bettermounthud-1.2.6.jar BetterPaleGarden-1.3-Fabric.jar betterscreens-2.0.9+1.21.10-fabric.jar betterspawnercontrol-1.21.10-4.7.jar BiomesOPlenty-fabric-1.21.10-21.10.0.3.jar blastingraw-1.21.10-fabric-3.2.jar blue-archive-halo-1.2.2-1.21.10.jar bottledair-1.21.10-2.5.jar breakfree-1.4.0.jar breezespawn-1.21.10-1.1.jar BridgingMod-2.6.3+1.21.10.fabric-release.jar Camerapture-1.10.8+mc1.21.9-fabric.jar chatanimation-1.0.7.jar chatsigninghider-fabric-1.21.10-1.0.5.jar chunksfadein-fabric-3.0.11-1.21.9.jar ClienThings 2.7.1 (1.21.9-1.21.10).jar cloth-config-20.0.149-fabric.jar Clumps-fabric-1.21.10-28.0.0.1.jar cobweb-fabric-1.21.10-1.4.0.jar collective-1.21.10-8.13.jar configurable-3.3.0+1.21.10-fabric.jar connected-doors-1.3+1.21.2.jar continuity-3.0.1-beta.2+1.21.10.jar coolrain-1.3.0-1.21.10.jar craftsense-1.21.9-v1.1.9.jar CrashAssistant-fabric-1.21.5-1.21.10-1.10.23.jar CreativeCore_FABRIC_v2.14.7_mc1.21.9.jar CreativeOnePunch-1.6-universal.jar cursors_extended-fabric-4.1.4+1.21.9.jar cwb-fabric-3.0.0+mc1.21.5.jar DeathFinder-v21.10.0+mc1.21.10-Fabric.jar deimos-1.21.10-fabric-2.5.jar DeleteNarrator-1.2.jar disableportalchecks-1.0.0.jar DistantFriends-fabric-1.21.10-0.13.0.jar DistantHorizons-2.3.6-b-1.21.10-fabric-neoforge.jar diversity-fabric-1.21.10-2.5.4.jar dontstopcrouching-1.0.0.jar dynamic-fps-3.10.1+minecraft-1.21.9-fabric.jar elytra_physics-fabric-2.4_mc1.21.9-10.jar enchdesc-fabric-1.21.10-21.10.1.jar enhanced_attack_indicator-1.2.0+1.21.6.jar explosive-enhancement-1.4.0-1.21.10.jar fabric-api-0.138.3+1.21.10.jar fabric-language-kotlin-1.13.7+kotlin.2.2.21.jar fadeless-2.0.5-1.21.9.jar faewulf_lib-fabric-1.21.10-1.3.2.jar FallingTree-1.21.10-1.21.10.1.jar fancy-door-anim-1.1.0.jar fancytoasts-fabric-1.21.10-1.4.5.jar ferritecore-8.0.0-fabric.jar firstperson-fabric-2.6.0-mc1.21.10.jar fnp_patcher-25.11.1+1.21.9.jar followersteleporttoo-1.21.10-2.7.jar ForgeConfigAPIPort-v21.10.1+mc1.21.10-Fabric.jar Fuzz-v1.6.5-mc1.21.10.jar geckolib-fabric-1.21.10-5.3-alpha-3.jar GlitchCore-fabric-1.21.10-21.10.0.4.jar GpuTape-1.0.6.1-1.21.8-1.21.10.jar haul-data-pack-1.3.2.jar immersive-hotbar-1.0.4-1.21.9.jar ImmersiveUI-FABRIC-0.3.5+1.21.9.jar InventoryProfilesNext-fabric-1.21.10-2.2.1.jar inventorytotem-1.21.10-3.4.jar iris-fabric-1.9.6+mc1.21.10.jar ItemPhysic_FABRIC_v1.8.11_mc1.21.9.jar jei-1.21.10-fabric-26.1.1.25.jar just-hammers-fabric-21.10.0.jar krypton-0.2.10.jar lambdabettergrass-2.5.0+1.21.9.jar lambdynamiclights-4.8.6+1.21.10.jar libIPN-fabric-1.21.10-6.6.1.jar libjf-3.19.4.jar lithium-fabric-0.20.0+mc1.21.10.jar lootr-fabric-1.21.10-1.18.31.98.jar LootrPolymer-1.1.jar macevariants-fabric-1.21.6-1.0.8a.jar Marlow's Crystal Optimizer-1.21.5-1.0.3.jar mcw-paintings-1.0.5-mc1.21.10fabric.jar mcw-roofs-2.3.2-mc1.21.10fabric.jar mcwbiomesoplenty-fabric-1.21.10-1.4.1.jar mob-captains-v3.4.0.jar mod-loading-screen-1.0.5.jar modernnetworking-fabric-1.2.3+1.21.10.jar modmenu-16.0.0-rc.1.jar monsters-in-the-closet-1.0.3+1.21.9.jar moreculling-fabric-1.21.9-1.5.0-beta.2.jar MouseTweaks-fabric-mc1.21.9-2.29.jar nethermap-4.2.0+1.21.5.jar no-resource-pack-warnings-1.4.0.jar nohostilesaroundcampfire-1.21.10-7.2.jar notenoughanimations-fabric-1.10.6-mc1.21.10.jar numeralping-1.2.7.jar nutritiousmilk-1.21.10-3.5.jar ok_zoomer-fabric-15.0.0-beta.2.jar owo-lib-0.12.24+1.21.9.jar panda-anti-lag-2.2.0_1.21.9+1.21.10.jar panda-tnt-fusion-1.0.0_1.21.9+1.21.10.jar PaperDoll-v21.10.0+mc1.21.10-Fabric.jar particular-1.21.10-Fabric-1.3.1.jar PatPat-1.2.3+1.21.10.jar PermanentSponges-v21.10.0+mc1.21.10-Fabric.jar PetOwner-1.8.11-1.21.10+.jar placeholder-api-2.8.0+1.21.9.jar plasmovoice-fabric-1.21.9-2.1.6.jar PlayerAnimationLibFabric-1.1.3+mc.1.21.9.jar polymer-bundled-0.14.3+1.21.10.jar polytone-1.21.10-3.6.3-fabric.jar prickle-fabric-1.21.10-21.10.2.jar pumpkillagersquest-1.21.10-4.8.jar PuzzlesLib-v21.10.8+mc1.21.10-Fabric.jar raknetify-fabric-0.1.0+alpha.5.193-all.jar reactivemusic-1.2.1+1.21.9.jar reeses-sodium-options-fabric-1.8.6+mc1.21.10.jar reflex-fabric-1.0.4+mc1.21.5.jar reinforced-chests-3.3.4-alpha+1.21.10.jar ResourcefulLib-fabric-1.21.9-3.9.1.jar respackopts-4.14.0.jar Revamped Shipwrecks 1.1.0.jar reverse-glass-block-panel-88.jar scorched-1.1.4c.jar servermonitor-1.5.0.jar ShatterLib-FABRIC-0.6.0.5+1.21.9.jar silk-all-1.11.4.jar SimpleDeathChest-1.3.2.jar simplefog-fabric-1.21.9-2.0.11.jar sit-1.21.10-29.jar skinlayers3d-fabric-1.9.2-mc1.21.10.jar skippy-pearls-1.5+1.21.9+Datapack.jar sleepwarp-2.9.0+1.21.9-rc1.jar slumber-1.3.1.jar slyde-1.7.13.jar smoke-suppression-1.2.6+MC1.21.2-1.21.10.jar SmoothBoot-FABRIC+1.21.10-1.0.0.jar SmoothScrollingRefurbished+1.21.9-rc1-1.5.0.jar sodium-extra-fabric-0.7.1+mc1.21.10.jar sodium-fabric-0.7.2+mc1.21.10.jar soothing-campfires-1.0.5.jar sound_physics_perfected-1.12.0+1.21.9-fabric.jar spawnanimations-v1.11.2-mc1.17-1.21.10-mod.jar status-effect-bars-1.0.9.jar stutterfix-1.0.0.jar superfastmath-0.0.2-1.21.10.jar talk_balloons-fabric-1.4.0+1.21.10.jar TerraBlender-fabric-1.21.10-21.10.0.0.jar timm-1.1-1.21.10.jar tlib-1.3.1-1.21.9-beta.jar tnt-timer-3.0.jar torch-hit-fabric-1.21.10-7.1.0.jar undergroundbeacons-1.21.10-1.0.jar Unwrecked Ships Plus 2.0.6.jar uuid-hex-1.2.jar variantsandventures-fabric-1.0.19+mc1.21.10.jar vcinteraction-fabric-1.21.10-1.0.8.jar veinminer 1.21.10 fabric.jar village-hero-plus-6.0.jar visualjukebox-1.0.4+1.21.9-rc1.jar VisualWorkbench-v21.10.0+mc1.21.10-Fabric.jar vmp-fabric-mc1.21.10-0.2.0+beta.7.217-all.jar voicechat-fabric-1.21.10-2.6.6.jar voicechat-names-1.1.0.jar webcam-fabric-4.4.1-1.21.9.jar whoami-1.0.jar wolfcompanion-4.0.0.jar woodworking-1.1.jar wthit-1.21.10-fabric-17.3.3.jar xaeros-map-server-utils-1.0.1.jar XaerosWorldMap_1.39.17_Fabric_1.21.9.jar Xaeros_Minimap_25.2.15_Fabric_1.21.9.jar yet_another_config_lib_v3-3.8.1+1.21.10-fabric.jar

Just a biig block of text, with all the mods i have. Nothing special!