Baby Fat - Polymerized
by tomalbrc
With Baby Fat - Polymerized installed on a server, players who own a ranchu goldfish can breed new variants, and the water lettuce plant appears in savanna water.
What it does
The Fabric server mod adds a new mob, the ranchu goldfish, along with a decorative aquatic plant called water lettuce. Ranchus spawn in river biomes and are almost always found as the default muddy-brown wild variant, with patterns carried by the bred offspring. Water lettuce spawns in water bodies within savanna biomes and can be spread with bone meal.
Breeding works differently from other mobs. A ranchu cannot be fed to breed; players must first catch it with a bucket to domesticate it. To pair two ranchus, they need to be placed in water under conditions that must be met, and once those are maintained the fish enter love mode on their own. The mod requires Polymer, which handles the server-side portion of its content, and players need no extra client-side mods for it to work.
Key features
Ranchu goldfish mob
A new fish spawns in river biomes and is bred with a bucket-domestication step before any breeding can happen.
101 color patterns and three tail sizes
Bred ranchus combine 101 color patterns with Short, Medium and Long tails, for 303 skin combinations in total.
Water lettuce plant
A decorative aquatic plant grows in savanna water bodies, and a green dye can be crafted from it.
Automatic breeding conditions
Ranchus in water that meets the required conditions enter love mode by themselves, so the server runs breeding without player input.
Polymer port
The server-side Polymer build is a port of the original Forge mod, and the credits go to its original authors and team.
Gallery
Compatibility
Latest build for each game version and loader.
26.x4 of 4 versions with builds
1.21.x12 of 12 versions with builds
1.20.x1 of 1 version with builds
This mod also publishes snapshot builds. Snapshots are not shown in the matrix.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Use cases
Who it’s for: Server owners running Fabric who want a themed aquatic mob and plant, and players who enjoy collecting and breeding fish variants on those servers.
How it compares
Polymerized Nether Ores is also a server-side only Fabric mod, but it targets 1.21.10 and adds ores, so it does not overlap with the fish. Breed Parrots With Seeds is client and server, released under the MIT License for 1.21 – 26.2, and it changes how parrots breed. Balanced Baby Zombies needs the server and is released under the GNU General Public License v3.0 only, but its environment and license differ from this mod.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Baby Fat - Polymerized | Fabric | 1.20.1 – 26.3 | Server-side only | 2026-10-01 |
| Polymerized Nether Ores | Fabric | 1.21.10 | Server-side only | 2026-02-03 |
| Breed Parrots With Seeds | Fabric | 1.21 – 26.2 | Client and server | 2026-08-07 |
| Balanced Baby Zombies | Fabric | 1.20.1 | Server required, client optional | 2025-06-27 |
Questions
Does Baby Fat - Polymerized need Polymer?
Which Minecraft versions are supported?
How is a ranchu bred in this mod?
In the catalog
Baby Fat - Polymerized is one of 11,058 Mobs mods on ModsFinder, and one of 5,189 Mobs mods for Fabric. 8,071 mods support Minecraft 26.3.
More from tomalbrc
Similar mods
What the author says
Credits go to the original authors: ### Coda ### bagu_chan ### Team Fusion This mod adds a new mob - Ranchu goldfish! They come in a variety of patterns, and can be bred. Alongside this, it also adds a new decorative plant - Water Lettuce.
Official listing
- Modrinth page
- modrinth.com/mod/baby-fat-polymer
- Owner
- tomalbrc
- Published
- 2024-08-27
- Updated on Modrinth
- 2026-10-01
- Facts verified
- 2026-10-15