From Halopedia, the Halo wiki
Minimates are a block-styled miniature action figure originally created by Art Asylum and now released by Diamond Select Toys.  The basic Minimate figure design has a 2" tall body that resembles an extremely simplified human form with 14 points of articulation, higher than average for block figures. Lines of Minimates have been released for numerous comic, TV series, movie and video game licenses and are primarily released to specialty retailers and aimed at adult collectors. They are currently creating Halo minimates, with the first sets being sold on October 6, 2010.