Macaulay Culkin was 4 in The Midnight Hour when he played the character 'Halloween Kid (uncredited)'.
That was over 39 years ago in 1985.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 43, and has starred in 36 movies in total, 36 of those since The Midnight Hour was released.
In The Midnight Hour, I think Macaulay Culkin looks: