When is Tobi from Naruto introduced?

[Danni A]

In the anime? (if in it, yet)

And do you know how old he is or what he looks like without his mask on? Thanks!

 

[«????d??» ?s o? ?????s !]

Tobi is first seen in Episode 32 of Naruto Shippuuden and takes Sasori's place in Akatsuki.

--- MAJOR SPOILER! ---

He is later revealed in 139 that Tobi is actually in fact Uchiha Madara. Tobi was just a fake persona of his so that he would not be suspected by people. And Madara is old, very old. He was present before Konoha was even built so that should tell you how long he's been alive for.

There's no clear picture of how he looks now, but in this screenshot of the episode, you can see a bit of his face.
http://naruto.wikia.com/wiki/File:Madara_slightly_taking_off_his_mask.JPG

This is how he looks when he was younger though.
http://naruto.wikia.com/wiki/File:-Madara_Uchiha-.JPG