What is a Halo action figure?

no most halo reach figures are smaller

for evry one you get you get a serten amoount of points and once you have like 1000 points you go to mcfearlane.com/halo points and you can get free stuff

Plastic.

Yes but not as many as Toys R Us

yes, they developed figurines of the masterchief and his alien opposition, these can be bought at gamestores such as gamestation, chips and game. hope this helps :)