The Subway is a unit in Metal Slug Attack. Originally unplayable (appearing in Attack! as a boss), it was for a time unlockable during in the Extra Ops titled "Halloween Train". As in the original Metal Slug series, the train simply charges towards the enemy while dealing rapid melee damage to anything that gets in its way. It lowers resistance very rapidly, causing knockback often. This makes it highly effective against units near its AP cost, though it will suffer greatly from knockback-counter units like Leona and Crazy Ralf. It also gains a suicide attack with File:MSA Skill small +.png 4 unlocked. Its large size, decent health pool and low AP cost makes it a good unit for shielding smaller units.