Ivar's Bosses
by ivarnvim
Ivar's Bosses adds four new bosses to NeoForge 1.21.1, each summoned through its own ritual and each with its own attack patterns.
What it does
The mod adds four bosses, among them the Spider Mother, who guards a path deep in the jungle and can spawn cave spider minions, and Fenrir, a spirit wolf sealed away in the magic amethyst caves that is described as the most dangerous boss of the set. Some bosses are awakened by specific items or conditions: the Spider Mother is roused by eating a Spider Eye at night, and Fenrir is summoned through an alchemical ritual that mixes sugar and pink dye in water. Fenrir also needs the Infinity Cave and Galosphere mods to be installed separately before it can be summoned.
The mod is installed on NeoForge only, for 1.21.1, and it runs on client and server, so the server and every player need it. It also overhauls the vanilla Warden and Ender Dragon with larger updates to their fights. The code is under the MIT License, and the mod is not open source.
Key features
Four new bosses
Four bosses are added, each with its own attack patterns and summoning method.
Ritual summoning
Some bosses appear only after a ritual, such as a bone-feeding sequence near three campfires or an alchemical mix.
Spider Mother minions
The Spider Mother can spawn cave spider minions during her fight in the jungle.
Vanilla boss overhauls
The Warden and the Ender Dragon receive larger changes to their fights than in vanilla.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Adventure progression
Each boss sits in a distinct location, from the jungle to deep caves, which gives exploration a set of goals beyond vanilla fights.
Who it’s for: Players who want more boss encounters in survival worlds, and server owners who run adventure maps with extra progression.
How it compares
CrownCrawl is also a NeoForge mod released under the MIT License, but it covers 1.21.1 – 1.21.8. Eternals is published for 1.21.8 only under All rights reserved. LAir's Bosses is also an MIT-licensed NeoForge mod, limited to 1.21.1, with the same client and server environment as Ivar's Bosses.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Ivar's Bosses | NeoForge | 1.21.1 | Client and server | 2026-07-12 |
| CrownCrawl | NeoForge | 1.21.1 – 1.21.8 | Client and server | 2025-07-29 |
| Eternals | NeoForge | 1.21.8 | Client and server | 2025-12-09 |
| LAir's Bosses | NeoForge | 1.21.1 | Client and server | 2024-12-08 |
Questions
Does Ivar's Bosses need other mods?
Does the mod have to be installed on the server?
Which loader and game version does Ivar's Bosses use?
In the catalog
Ivar's Bosses is one of 11,058 Mobs mods on ModsFinder, and one of 4,974 Mobs mods for NeoForge. 32,366 mods support Minecraft 1.21.1.
Similar mods
What the author says
Fang – The mighty guardian of the forest. He can be summoned at night by lighting three campfires in a triangular formation and feeding a bone to a tamed wolf in the center. Spider Mother – She will block your path deep within the jungle, possessing the ability to spawn cave spider minions. You can awaken her by…
Official listing
- Modrinth page
- modrinth.com/mod/ivars-bosses
- Owner
- ivarnvim
- Published
- 2026-07-12
- Updated on Modrinth
- 2026-07-12
- Facts verified
- 2026-10-15