Splashlight by BioToy is a squirt gun that shoots bioluminescent water that glows in the dark. The toy uses natural bioluminescent proteins to create its effect.
The secret is in the ReLumes (the bioluminescent fuel) which makes the water light up. We make the ReLumes with natural bioluminescent proteins, so they are non-toxic and do not stain. Each blast of water from the SplashLight will glow and make your target glow for up to a few minutes. Drench one target in glowing water, or hit as many targets as you can.
via reddit, The Awesomer