
Mario first appeared as "Jumpman" in Miyamoto's first game, Donkey Kong. He was named Jumpman because there were no other ideas. I'm uncertain to whom he was named after later on (it dealt with Nintendo's first warehouse. I think it was the name of the janitor who resembled Mario), but after this person, Jumpman was a thing of the past as Mario became his new name.
The irony to Mario is that he has looked almost the same for all these years. But why does Mario look the way he does? It deals with the technical limitations of the arcade systems of back then. The reason Mario has a moustache is because it made it easier to see that Mario had a nose and a distinguishable mouth. He had a hat because Miyamoto couldn't show his hair moving, so a hat covered that up. His overalls helped gamers see his arms and his body better. Back then in Donkey Kong, Mario had red overalls and a blue shirt. This was changed to the opposite (blue shirt and red overalls) in Mario Bros. In Super Mario Bros., Mario had red overalls and a brown shirt, but reverted back to his blue shirt and red overalls in Super Mario Bros. 2. Mario's look has remained constant since then.
Mario has appeared in dozens of games since his debut. His latest game is Super Mario Sunshine. In it, Mario uses the water-spurting FLUDD as an item. And over the years, Mario has gained other abilities, such as the ability to grow, fly, turn into a racoon, ride Yoshi, etc.
In Super Mario Bros., Shigeru Miyamoto had much more advanced technology than the arcades he worked with. Mario was originally intended to be "big" the entire game. But instead, if Mario ate a Mushroom, he would grow in size, which enabled him to take another hit. Miyamoto-san's inspiration for this came from Alice in Wonderland.
Mario has played a number of side roles as well, such as a doctor. He also enjoys throwing parties, and playing golf and tennis. He even is the villan in Donkey Kong Jr.! He captures Donkey Kong and has you playing as Donkey Kong Jr. All in all, Mario has been in around fifty games and is the most popular video game character. In fact, research has suggested that Mario is even more popular than Bugs Bunny!