Ian Barker is the main protagonist of the first Goosebumps SlappyWorld book, Slappy Birthday to You.
History
Ian always wanted a ventriloquist dummy, it's something he always wanted since he was nine years old, then he gets Slappy on his twelfth birthday, and he couldn't be happier, until his cousins read the magic words that bring Slappy back to life.
Slappy begins causing trouble, and Ian get's blamed for the thing's he does, but one night, Slappy disappears; his cousins Jonny and Vinny stole him, but that was a bad idea.
In the end, Slappy brings to life an army of broken dolls, including Abigail, who eventually stops Slappy.
Personality
Ian is a determined boy, when he has a dream, he always wants it to come true, he is also quite the entertainer, but he's not very strong. When something is wrong, he knows right away that he has seen what he's seen.