Has anyone figured out which sockpuppetry Grue belongs to?

I met a Grue, "Said how do you do?"
Said, "How do you do, too?"
To which I replied, "Fine by you."
Not so true, Grue.
If by inferring Grue not true,
Could Grue still be true to you?
Perhaps it is not Grue by GNU,
Or Grue by U?
But grew by Grue that rings true.
Time flew, "Must be going, Grue."
Uncomfortable pause grew...
Grue knew that apart from that,
Grue had to know that,
Time flew, glad that,
Moving past,
Uncomfortable moment, thought,
"Well, that's enough of that!"

FF