You gag on the blue sludge suddenly smothering you, wrapping around your body like an eel as you struggle and squirm in an attempt to get away. The goo squelches through your body, something squirming amidst your rapidly changing organs. Your struggles peeter away, body swaying as it changes.
There's a ripping noise as a tail comes into existence, breaking your shorts, which fall to the floor. You think it's almost done when the squirming solidifies, to your startlement. You peer back in shock as fish- goo just like you- swim through your new body like it's water... This will take some getting used to...