When hit mobs may fall a block through the ground and will continue attacking, hitting the mob again fixes this. I have only seen this underground and falling through stone blocks
Environment
Windows 8 (And Windows 7), java 7u67 (64 bit)
MC-71921
Mobs can fall through blocks when hit
Resolved
Duplicate
0
This issue is a duplicate of MC-119. It has been linked to the original bugreport.
Please search before reporting any bugs, as it's likely that one exists already.