There was a big box near the wooden bridge, nestled into the rock garden, labelled "Fish Mutator." There was a big shiny red button on top. And a little sticker that said "Please don't mutate the fish."
I pressed the button, and a fish suddenly gained telepathy and the power to swim through walls. And also a degenerative bone disorder.
A volunteer told me that I shouldn't have pressed the button, and asked me to leave.