Board Thread:Questions and Answers/@comment-27606805-20160114003153/@comment-29449108-20160130135428

Wri-El man, youre obsessed with Vastolordes. This forum is about stark being a natural arrancar. You keep rambling on to other topics and it makes it hard to continue a discussion, lest we just ignore your posts. Ulquiorra was shown to become an arrancar without Aizens help. That is canon, drawn by Kubo himself.

As for the OP, well, clearly he was a natural Arrancar because he was already one when Aizen first met him, ergo Aizen cant have created him and the fact that we saw Ulquiorra and even at the very begining of Bleach, the substitute shinigami arc, grandfisher was created as one by other arrancar, not Aizen and the hogyoku. So we know it is very possible