[MCPE-17651] Only Strays spawn in various frozen biomes

In various frozen biomes, the only hostile mobs that spawn are the skeletons (as expected most of them spawn as strays).

Steps to reproduce:

Create and open a new world with seed 297169206, mob spawning disabled, and always day selected.
Issue the command /time set midnight.
Issue the command /tp 626 86 -285.
Issue the command /gamerule domobspawning true.
Wait until a bunch of mobs have spawned.
Issue the command /kill @e[family=monster]. Note that only strays were present to be killed.

Additional information:

The pinned comment contains root cause analysis. In short, the biome JSON files are missing the "monster" tag.

Affected biomes:

Frozen River (frozen_river)
Legacy Frozen Ocean (legacy_frozen_ocean) - no longer generate in new worlds
Snowy Mountains (ice_mountains) - no longer generate in new worlds
Snowy Plains (ice_plains)

This report (including comments) uses a mixture of Bedrock and Java biome names. The following table can be used to translate the Java names to Bedrock biome names.

Java Name	Bedrock Name
Snowy Tundra	Ice Plains
Snowy Mountains	Ice Mountains
Snowy Taiga	Cold Taiga
Snowy Taiga Hills	Cold Taiga Hills

Linked issues

is duplicated by 6

BDS-4421 Snowy biome only spawn strays Resolved

MCPE-62900 Monster Bug in the Snowfield Resolved

MCPE-105731 There are only strays that spawn in snowy tundra biome and snowy mountain biome as hostile mobs Resolved

MCPE-129886 Phantom spawning Resolved

MCPE-178929 Only stray spawn on the surface of snow plains Resolved

1 more links

relates to 3

MCPE-161245 Monsters do not spawn in in the river biome Open

MCPE-151411 Skeletons not spawning in Frozen Ocean and Deep Frozen Ocean biomes (not even spawning in caves) Open

MCPE-170183 Monsters do not spawn in mangrove swamps (except slimes and bogged) Resolved

Comments 22

Tasel 2016-11-01T15:05:42Z

Partially able to confirm. Unsure if other entities walk into biome or just have very very low spawn chance. However does seem to only be strays and skeletons seem to be spawning. Underground I'm only finding those mobs and no other type.

Running on iPad Pro iOS 10 PEv16.

Tasel 2016-11-02T17:25:07Z

Also not sure if related, separate issue, or a realms issue: When on a Realm in ice plains, there are so many spawned skeletons/strays that the server starts to lag. I'm the only one logged in, and can see them jumping forward multiple blocks. Logging out and back in does not solve issue. Waiting for daytime kills some of them, but beyond those taking refuge in shade, assumption is there are many in caves below and/or spawned with armor to protect from sun to prevent being burned. Was so bad I had to stop playing cause I couldn't move without being killed repeatedly.

Note: many are dying as the ground seems little red with bones and arrows. But sheer numbers of spawned mobs makes ratio that survives unplayable.

Vegito Rekt 2016-11-20T04:19:51Z

This happens in 0.17.0.2
If you want a good seed to test this for yourself try the seed ibxspawn2 with the world type set to "old"

[Mod] Celesian 2016-12-10T16:40:49Z

I am unable to reproduce this bug in v.1.0.0.2

Test: used the seed "ibxspawn2" and a single creeper spawned and a zombie

Tasel 2016-12-12T21:34:21Z

I believe this issue isn't what it first appears to be.
I'm in a realm where originally only Skeleton's and Stray's were spawning in the ice plains. I have since built a fairly large structure and lite up most of the area. I've also taken care to kill the Skeleton's and Stray's that are not being automatically killed when at Sunrise due to armor. And since doing this I now have seen creepers, spiders, and zombies also appear.

I believe the issue to be due to the apparent higher than normal spawn levels of Stray's and Skeletons, and that they often will spawn with protective armor. If left alone, they will stay, and the following night another larger number of Skeleton/Stray's spawn, again with a % with protection. Between their ranged attack causing it difficult to kill them in large numbers, and this (seemingly) higher spawn level, it appears that the overall mob level quota gets reached, allowing for no more spawns, and therefore no more zombies, creepers, or spiders to be able to spawn. Does anyone know if this assumption is correct? Do ice plains allow for higher level of spawns? Or is it that both skeletons and strays have different levels that can be reached, eventually blocking off any other type of mob?

12 more comments

Specialistol 2016-12-13T05:45:53Z

Except in your theory, armored zombies would also have stayed.
I was collecting loot (which consist only of bones and arrows) every dawn (after they burned) and kill the remaining (which were only skeletons), to have a clean slate for the next day. I had this process repeated for 10 straight (in game) days, until it was enough of a hassle to go down at every dawn (I was building a snow tower). So it isn't mob limits or visual bias.

Regardless, report claims it no longer repros, I guess we'll find out in a few months when 1.0 releases, or if they decide to integrate fixes back to 0.16.

Tasel 2016-12-13T15:40:00Z

Of possible relevance: http://www.minecraftforum.net/forums/minecraft-discussion/survival-mode/2640790-killed-armor-almost-destroyed-by-skeleton-while?page=2

Could it be that there is code to allow for spawning on snow for Strays (and therefore Skeletons)? Thus only when you start having torches down and clean blocks available would non-skeletons spawn. I know for a fact that Skeletons and Strays can spawn on snow. Don't know about other mobs.

silentwisperer 2019-02-09T05:00:18Z

This issue has been readded to the game, is very easy to spot in current bedrock updates. Please re-open this report!

Auldrick 2019-02-14T14:42:08Z

Confirmed in 1.9.0 using Windows 10 and the seed and coordinates given in the description. Only strays spawned on the surface, not even skeletons. This was repeated in several tests after switching to Peaceful and back. The only mobs I found in caves were zombies that were presumably spawned by a dungeon spawner next to them and one stray that probably wandered in from the surface. The number of strays spawned on the surface seemed excessive. This may have been either a cause or a consequence of no other hostile mobs spawning. I could speculate that the monster spawning algorithm, after determining that this is an ice spikes biome, incorrectly tests whether a skeleton is being spawned and replaces all spawned mobs with strays.

Jim Lacy 2019-02-17T09:21:51Z

I have also seen this on xbox one bedrock 1.9.0

Only hostile spawn was surface strays at night. No cave spawn at all was detected by me. No hostile spawn at all during the day (which probably proves that no cave spawn was occurring)

seed = -904515

coords = 1671, 12, 1861 where I had carved out a view point for a slime chunk which is at 1664/1888, 1679/1903

No slime spawned at all and no hostile mobs even when I had removed lighting. There should have been a lot of slime during the day because there were no hostile mobs at all. Confirmed with commands to kill entities

Biome was snowy tundra (according to chunkbase)

Thanks,

MUHAMMAD ARIF BIN JEFRI 2020-04-20T02:26:19Z

Guys. Ice biomes are supposed to only spawn strays. It's just how the biome works

GoldenHelmet 2020-04-23T19:55:46Z

Tested and confirmed in 1.14.60 using seed provided in the description. I got the same results as Auldrik got in 1.9: only strays spawn in the snowy tundra. According to the wiki entry, this applies applies to snowy mountains as well.

I also looked at the spawning .json files. The problem appears to be that the affected biomes lack the "monster" biome tag. Strays require the "frozen" tag but do not require the "monster" tag, so they are able to spawn in all frozen biomes. Since strays spawn only on the surface, the result is that underground, snowy tundra (and mountains) are just like mushroom fields.

Euwill Eusebio 2020-05-30T15:45:43Z

Confirmed to also affect 1.16.0.64

蹇子铭 2020-11-16T01:44:59Z

I have checked the file of ice plain biome and ice mountains biome, and I found that there is a 'frozen' tag in this file, which controls the spawning of the strays, but no 'monster' tag in it, which controls the spawing of the zombies, spiders, skeletons and creepers. As far as I am concerned, it must be a negligence to have omitted the 'monster' tag, causing there are only strays in the snowy tundra and snowy mountain.

蹇子铭 2020-11-16T04:08:19Z

Additionally, in Minecraft Java edition, hostile mobs, such as zombies, skeletons, spiders and creepers, can spawn normally.

DeeFeeCee 2020-12-01T03:34:36Z

Affects 1.16.100. Appears to affect snowy tundra, snowy mountains. & frozen river. Ice spikes. snowy taiga, & snowy taiga hills are fine.

Natthan 2021-09-23T14:19:06Z

Affects 1.17.40.21
Affects 1.17.30

Yacoub Mezni 2021-10-23T13:00:04Z

Affects 1.18.0.22 beta

EwokSithLord747 2024-07-25T14:17:58Z

The issue is the biome is missing the 'Monster' tag which is causing all normal monsters not to spawn.

Strays look for the cold and frozen tags so they can still spawn, and are the only mob that spawns.

GoldenHelmet 2024-08-15T12:27:33Z

This bug is not fixed. ice_plains.biome.json still does not have the monster tag.

Auldrick 2024-08-15T12:49:10Z

Reopened because my earlier tests were finding other mobs in adjacent biomes, not in the ice plains as I believed. I have replaced the coordinates in the description to avoid this. Please test at the new coordinates.

Minecraft386882 2024-11-10T14:15:40Z

Confirmed in 1.21.44