Or So He Sphinx

I'm not the one you should be approaching.
All wrapped in riddles
untouched by
consideration
only answers

I'm not the one you're after

Which creature at first goes on four legs?
By mid-day two, by evening three?
With each leg added
it grows weaker

What creature could this be?

There are two sisters
close, so close.
One births the other,
and in turn she

then bears her sister.
By what device

Could these two sisters be?

You're such a fascinating subject
Tell me who built you, feline girl
Out in the desert
what surrounds you?

Nothing but rhymes and sand dunes.

I'm not so sure that we're all alone here
I think I'm in love with every one
That silken promise so dismissive
I think I'll just go home now

Our blurring boarders, so confounding
Where you begin and where I end
Chimera, crossbreed our composition
Nothing but rhymes and sand dunes