Abstract: A toy water gun includes a hand-held body having a water reservoir capable of storing a predetermined quantity of water therein, and a guide rail engaged with the water reservoir. The toy water gun further includes a hand-operated pump mechanism is in fluid communication with the water reservoir and dynamically engaged with the guide rail, a discharge nozzle in fluid communication with the water reservoir and having an illuminable water trajectory selectively egressed distally away therefrom, and a light emitting mechanism attached to a dynamic portion of the pump mechanism. Advantageously, the dynamic portion of the pump mechanism and the light emitting source are contemporaneously reciprocated along a bi-directional travel path relative to a position of the discharge nozzle and thereby illuminate the illuminable water trajectory after being egressed from the discharge nozzle.