[@Ariamis] not entirely sure if this is right, but I'll try and explain things as I believe them to be (within the Madoka universe).

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So, there are the Witches Familiars; creatures born on a Witches Labyrinth upon creation. These Familiars are... Eh, reasonably powerful, and have a sole purpose to help protect both the Labyrinth and the Witch herself. These Familiars do not split from the Witch, and therefore do not become Witches.

The second type are [i]Roaming Familiars[/i], which are born of Witches when they grew too much (and outweigh their own ToF with their power). These Familiars are capable of distorting space to change the way it looks with their presence, but do not actually create Labyrinths. This space has the exact same layout as the space that is distorted, and has the exact same entrances and exits as the surrounding area. These Familiars, after eating enough people/MGs, will evolve to become Witches, and in turn create more Familiars.


For Labyrinths, I'm fairly certain most Witches WILL change the place of their Labyrinth over time (as seen with Octavia). A person should, in theory, escape a Labyrinth if the Witch moves, though it is possible that, because Labyrinths are so small in size, the person inside would simply move with it. 

According to the wiki, a Labyrinth takes the form of a MG's mental landscape at the time of becoming a Witch, with themes taken from the area that they BECAME a Witch within (the train tracks on Octavia's). As you enter deeper into it, the scape becomes less real and more like a mental landscape, with references to the Witch becoming more and more common.

Therefore, it is possible that the deeper into the Labyrinth you are, the less likely you are to escape it in case it moves. However, there are no ways to tell because no one (as far as I'm aware) has ever BEEN stuck in a Labyrinth when it moved.
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