When boys reach around the age of 9 or 10 the enter the stage of development known as the Tween years. This is a strange and confusion time when he is stuck between being a child and a teen. You may find that he still wants to play catch with dad, but only when no one is looking; or that suddenly there are girls starting to knock at your door to hang our with your son. These are two sure signs that the tween years are here.
This Halloween, let him assert his independence and shop for whatever Halloween costume he wants. Its time to let him express himself even if you don't like it. Just because he still fits in boy's sizes doesn't mean he is still little. Tweens may still fit into boys sizes but they want to look cool. Suddenly, a superhero is not cool anymore; a surefire sign your son is now a tween. He wants something with more attitude so he can express his sense of rebellion. For example, the Boys Punk Creep Tween costume has punk style and scary zombie-monster elements that those in this age group love.