Tobi (doesn't tell anyone he's Obito and never takes off his mask) has short black hair, an orange mask that covers all of his face except for his right eye, a slim and narrow build, wears a black robe with white and red clouds, and has a Sharingan, Reagan and fair skin. 

He's a very goofy and playful person when he's being Tobi, having a higher and more exaggerated voice, and being more serious and thoughtful when being Madara, taking a deep and demanding tone. 31 years old, 5'11" in height.