Rendering rotations for shulkers are set in onInitialSpawn method
MCP 9.35 rc1 names
The bug
The rendering rotation for shulkers are set in the net.minecraft.entity.monster.EntityShulker.onInitialSpawn(DifficultyInstance, IEntityLivingData) method. This means that shulkers with at least one NBT tag are not rendered correctly in spawners.
How to reproduce
/give @p spawner{BlockEntityTag:{SpawnData:{id:"minecraft:shulker",AnyNbtTag:0},Delay:12000s}}
Created Issue:
Rendering rotations for shulkers are set in {{onInitialSpawn}} method
MCP 9.35 rc1 names
The bug
The rendering rotation for shulkers are set in the net.minecraft.entity.monster.EntityShulker.onInitialSpawn(DifficultyInstance, IEntityLivingData) method. This means that shulkers with at least one NBT tag are not rendered correctly in spawners.
How to reproduce
/give @p mob_spawner 1 0 {BlockEntityTag:{SpawnPotentials:[{Entity:{id:"minecraft:shulker",AnyNbtTag:0},Weight:1}],Delay:-1s}}
Rendering rotations for shulkers are set in{{onInitialSpawn}}method
MCP 9.35 rc1 names
The bug
The rendering rotation for shulkers are set in the net.minecraft.entity.monster.EntityShulker.onInitialSpawn(DifficultyInstance, IEntityLivingData) method. This means that shulkers with at least one NBT tag are not rendered correctly in spawners.
How to reproduce
/give @p mob_spawner 1 0 {BlockEntityTag:{SpawnPotentials:[{Entity:{id:"minecraft:shulker",AnyNbtTag:0},Weight:1}],Delay:-1s}}MCP 9.35 rc1 names
The bug
The rendering rotation for shulkers are set in the net.minecraft.entity.monster.EntityShulker.onInitialSpawn(DifficultyInstance, IEntityLivingData) method. This means that shulkers with at least one NBT tag are not rendered correctly in spawners.
How to reproduce
/give @p mob_spawner 1 0 {BlockEntityTag:{SpawnData:{id:"minecraft:shulker",AnyNbtTag:0},Delay:12000s}}
MCP 9.35 rc1 names
The bug
The rendering rotation for shulkers are set in the net.minecraft.entity.monster.EntityShulker.onInitialSpawn(DifficultyInstance, IEntityLivingData) method. This means that shulkers with at least one NBT tag are not rendered correctly in spawners.
How to reproduce
/give @pmob_spawner1 0{BlockEntityTag:{SpawnData:{id:"minecraft:shulker",AnyNbtTag:0},Delay:12000s}}
For shulkers as well as soon as you provide on additional NBT tag (tag does not have to be valid):
/give @p mob_spawner 1 0 {BlockEntityTag:{SpawnPotentials:[{Entity:{id:"minecraft:shulker",CustomNbtTag:0},Weight:1}],Delay:-1s}}
Edit: This is MC-111381
Confirmed for 1.13.1.