The Goldfish is a neutral aquatic mob. The goldfish has multiple sizes (similar to slimes and phantoms), but can grow in size by consuming other mobs, such as baby mosquitoes. Small goldfish are passive to the player, and will not fight back even if attacked, but at a large enough size, they become hostile. Fortunately for their potential victims, goldfish shrink over time if not fed.
Goldfish can be useful to players due to their ability to eat mosquitoes while they're still babies. Players can use goldfish to guard water reservoirs and prevent mosquito spawning. Very large goldfish could also be used as guards, thanks to their willingness to eat players.
Goldfish can still spawn on peaceful difficulty, though they cannot do any damage to the player; However, large goldfish can still potentially cause the player to drown with their knockback.
Size[]
Goldfish start off a little over half a block long, but can eat various mobs to grow larger. Each mob eaten grants a point, and a larger and larger sum of points is required to grow again with each size. Every 5 minutes without any food removes a point, but once the goldfish reaches its fifth size (at which point it becomes hostile to the player), this will no longer be in effect.
Edible mobs[]
This table shows what mobs the goldfish will attempt to eat. Mobs in italics will normally fly and thus never be in the water to be eaten in the first place, unless pushed by a piston, spawned into it by a spawn egg, etc.
All mobs eaten by a smaller goldfish can also be eaten by a larger one.
| Size | Length | Damage (Hard Difficulty) | Mobs | Points |
|---|---|---|---|---|
| Small (1) | ~1/2 block | 2 |
|
— |
| Medium (2) | ~3/4 block | 4 |
|
16 |
| Large (3) | ~1.5 blocks | 5 |
|
48 |
| Very large (4) | 2.3 blocks | 7 |
|
80 |
| Giant (5) | 3.5 blocks | 8 |
|
148 |