Infantry is an Assist Trophy in Super Smash Bros. Brawl, taken from the Advance Wars series. Upon being unleashed from the trophy, GBA sprites of infantry and tanks will emerge, shooting bullets and missiles, which will damage any opposing players. Much like Excitebike and Lakitu, this Assist Trophy is represented by actual sprites from the original game.
This AT has not yet been confirmed on the Dojo, but has been seen in a gameplay video.