The Railgun is the special tower of the Only My Railgun Special Mission. It is like a Dartling Gun that shoots 3 darts
at once (it's like 3 Dartling Guns crumped together into one) but it can be upgraded to 4/4 and each upgrade only cost twice as expensive as its responsive upgrade for the Dartling Gun (seeing how it's 3 times stronger...). For the Ray of Doom upgrade, it won't shoot 3 Rays of Doom, instead it'll shoot a blue Ray of the Apocalypse that have the good old infinite pierce and can pop bloons thrice as fast! If the Railgun is upgrade to 4/4, it'll shoot that deadly beam AND shoot 9 Hydra Missiles at once AND have that ability that will kill 300 bloons instead of 100! Its appearance is a Dartling Gun with 2 more visible "guns", an extra yellow line and golden handle.