You seem to encounter a dark figure, He seems to be bearing an appearance similar to a Heartless, Although when looked at closely, It would have deep dark shades of blue on its skin, and it had glowing yellow eyes, Plus...He also had a similar appearance to Sora.

He would seem to notice you, crawling towards you on all fours.

...

Seems like He can't talk, But...at least you can.

Why not try striking a conversation with it?