I've given it some thought and I'm leaning towards ... Drakkosha.
Argument 1: Drakkosha is half-Dragon (scales) and half-Cat (cats, as everyone knows, love fish). It's very likely that the scales could belong to her.
Argument 2: Drakkosha is a well-known artist on the forum, and while shooting at Zubr at night, she could have easily forgotten a jar of water at the crime scene.
I think that, overall, these are quite strong pieces of evidence that should be considered...
Where do we end up when we save the world?