What is the true name for Kyubey? Through out the series the Magical Girls call it Kyubey however they respond just as well to Homura when she calls them Incubator and don't go to correct her.

I am wondering which is their real name, Kyubey or Incubator?
The name Kyubey is a short-hand for Incubator (pronounced [in-kyuh-bey-ter](source), which shows similar phonetic pronunciations). This follows a pattern similar to other nicknames or names that are shortened, such as:

&quot;Ed&quot;, from &quot;Edward&quot; (e.g. Edward &quot;Ed&quot; Elric from FMA) and
&quot;Al&quot;, from &quot;Alphonse&quot; (like Alphonse &quot;Al&quot; Elric, also from FMA).

That said, Kyubey is the name of the creatures, whereas Incubator is its race/species.
From the Madoka Magica wiki:

Kyubey is an Incubator/Messenger of Magic. Because of this, he, like his race, cannot exhibit emotions of any kind.

In episode 8, around 20:10, Homura says

I won't let things go according to your plans, Kyubey.
Or should I say... &quot;Incubator&quot;?

Which would be equivalent, in context, to me saying

I won't let things go according to your plans, Memor-X.
Or should I say... &quot;Human&quot;?