There's a little fish hiding on your system -- making its journey throughout GNOME 2 to MATE.
To let the fish swim for a while, press ALT+F2 and type:
free the fish
Wait a moment..... oh, hello, there you are. 
Pretty cool, huh? 
3 Likes
hahahahahahahahaha…love it!
1 Like
if you want to unfree the fish without having to logout,
pkill mate-panel
your panels will briefly disappear, then come back without any pesky piscines
Or just click on the fish.
for me, the fish comes back a short while after clicking it