(is either vanilla 1.6.3 singleplayer world or lan server me alone)

I found this glitched zombie for a third time. It was always a baby zombie, it is stuck as if it has no AI, and does not burn in sunlight.(but successfully despawns)

I don't know much about commands or mob attributes, but there were some things I could know.

As 'OnGround' is false, its not even standing on the ground unlike how it appears.

Also, the order of data in "Attribute" section seems like mixed up(2nd and 3rd picture), different from it of a general zombie spawned from commands(4th and 5th picture)

So I guess when an error occurs when an attempt to spawn zombie is made, it produces a glitched zombie.