Who is Tobi from Naruto because you never watch that show and your friend is obsessed with it so you just want to know a little bit about it Can anybody help please?

Tobi is Madara Uchiha, the same person who challanged the Shodaime Hokage at the Valley of the End. He also used his Eternal Mangekyo Sharigan to control Kyuubi into attacking the leaf village (Konoha). He is also the leader of Akatsuki.