Bottle of water (or any other liquid)

[FlawlessHappiness]

It shouldn't be necessary to be water, it could be a texture with animations that moved. But, I think that's just very complicated.
It's a good suggestion, though.

Off-topic: Do you seriously use that sniper? Because that video is yours, right? I prefer another one (which name I don't know because my TF2 is in spanish)

It should be very complicated. It's like adding a whole new lantern with physics and more animations...

Off-topic: It's actually a good sniper! When you scope long enough it deals serious damage