Diffrent question.

[nowofresh]

Can I create new ID for skin ? for example. 999

Can I get TXD skin for this (new) ID ?

Is this skin will be gameplaly ?

[12p]

no, no, and no.

[Oz.]

You can replace an existing ped's TXD, so long as the new TXD's texture is compatible with the texture mapping in the DFF (that is, face/arms/legs etc have to appear in the same places as in the original texture). You can't replace the DFF nor can you add new peds, as answered above.

Nowofresh, the answers to 90% of the questions you are asking can be found either by Googling it, or using the Search function on the forums. I'm sure this query has been raised dozens of times already.