Mobs can be spawned inside of fences and walls using spawn eggs.
By holding a spawn egg and using it on the block below a fence or wall, one can spawn mobs inside of fences.
Environment
Version 1.16.5, OS: Windows 10,
Linked Issues
Created Issue:
Mobs can be spawned inside of fences and walls using spawn eggs.
By holding a spawn egg and using it on the block below a fence or wall, one can spawn mobs inside of fences.
Environment
Version 1.16.5, OS: Windows 10,
Added Affects Versions: 21w05b
Added Linked Issues:
duplicates


Relates to MC-103934
Can confirm.
Can confirm in 21w05a.
This actually appears to be a duplicate of MC-186596.