Forge Mods for Minecraft 1.21
Browse 26 free Forge mods for Minecraft 1.21 — popular picks include Withering Heights: Revamped Wither, Zombie Nightmare Expansions - Undead Horror Monsters, CRYPTID.
Updated daily
Withering Heights: Revamped Wither
Turning the Wither into something worth calling a boss.
Zombie Nightmare Expansions - Undead Horror Monsters
Adds various creepy undead entities with unique mechanics and intricate designs
CRYPTID
Unique horror mod where your world comes alive. Adds 30 new cryptids and 40 new events. Now updated for slower gameplay
Zombie Horsemen
Zombie Horsemen is a Minecraft datapack that introduces a new surprise event similar to the Skeleton Trap. When triggered, a zombie riding a zombie horse, equipped with an iron helmet, iron axe, and shield, will spawn to challenge players.
oSzoukaua's: Realistic Spiders
This pack makes spiders more realistic! and much cuter!
Brutal Nightmare : Insane Difficult
Minecraft too easy? Try this mods with nearly 40 modifiers - settings new mini bosses, which made minecraft become hard & insane. Enhanced hostile mobs' AI & Angry passive mob. Zombie place/break blocks. Skeleton,Spider,Creeper,Enderman.
Too Much XP (TME)
Yeets the laggy XP orbs, whilst still maintaining a high level count

Wind Boost Enchantment
Allows one to Enchant the Harness with a Custom Enchant to make Happy Ghasts Faster
Bucketable
Put any mob into a bucket! Completely customizable!
Injured Effects
This mod adds effects to being low on HP! This applies to players, aswell as humanoid entities like villagers, illagers, and piglins!
Piglin Conservatory v3.0
Adds a news structure to the Nether, The Piglin Conservatory, along with a new Obsidian Apple, Dragon Fruit, Toxic Mushrooms, Hoglins' Fossils, Corrupted Emerald and a New Music Discs!
Sanity: Renewed
Brings the sanity mechanic from Don't Starve into Minecraft
Corner Entity
is an atmospheric horror mod that turns your peaceful Minecraft survival into a nerve-wracking experience. You will never feel truly safe again, as something is watching you from the shadows, waiting for the perfect moment to strike.
Mebahel's Skeleton Revival
When death is no longer the end… their skulls flee to rise again. Summon, hunt, or suffer — in Mebahel’s Skeleton Revival, every skeleton gets a second chance.
JerkSteve
Adds the most annoying mob to Minecraft, as seen in the viral meme videos.
Cave Dweller Overhaul
Overhauls the Cave Dweller with improved AI, features adapted from the original and Bedrock versions, plus some new additions
Simple Gravity Changer
This datapack adds a function to change the gravity of the world.
Colly SMP [NO LONGER UPDATING]
The Official Datapack used in the Colly SMP, no changes, no tweaks, THE REAL DEAL!
Succession
What if the world remembered what you did to it?
Better Entity Control
Take full control over mob and projectile attributes — modify health, damage, speed, armor, knockback, scale for mobs, and damage, speed, gravity, knockback for projectiles, with commands in Russian and English.
Chaos Chickens
Unpredictable Chaos Chickens ready to ruin your day.
Garfeldi [Cobblemon]
Back in 2024, I made an April Fools' addon for Cobblemon just called "Garfeldi", ironically posted to the Cobblemon server on April 2nd. I found the files, like, 10 minutes ago, made minimal changes, and decided to post it to Modrinth.
More Realism (MR)
This project helps you experience your world more realistically.
You Can't Sleep
A about bed sleep's horror mod

Slimes Everywhere
Allows Slimes to spawn at night in any biome
Zombie Nightmare Expansions Mod (1.21.1, 1.20.1) – Undead Horror Monsters
Zombie Nightmare Expansions Mod adds multiple high-detail undead creatures with different mechanics, combat styles, and special drops. The mod is designed for horror, zombie apocalypse, RPG, and hardcore gameplay packs. Features: Undead Mobs Disemboweler Large heavy zombie variant Targets players and cows High melee damage Drops Deathly Heart Tormented Zombie Disguises itself as a normal […]