If you type /summon MinecartSpawner, or get a spawner minecart any other way, the minecartspawner will have a full-size pig hovering above it. The pig will remain after you kill the spawner, and can't be killed or hit. It is just sitting there, unmoving, until you relog.
Linked issues
is duplicated by 3
Comments 6
Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases. If this has been done, we can reopen the issue.
Keep in mind that the "Resolved"-Status on this ticket just means "Answered", and that we are waiting for further information on whether this issue still exists or not. We will reopen it as soon as the requested information has been delivered.
The pig that remains is a ghost, relogging removes it. There is also a rotating miniature pig that sticks outside of the bounds of the spawner, and can be seen inside the back of the full pig.