I ruined a perfectly good iMac G4 1.25GHz by crunching the top RAM module while putting it back together, and damaged the logic board in the process (I'm not this hamfisted very often ).
So, I decided to put the carcass to good use, and gutted the insides. Then I took the monitor off and cut the back piece into a flower shape.
I still regret gutting an iMac G3 3y ago to make it a cat's home.
Unfortunately the keyboard wasn't hooked up. The laptop I used for the screen behind the tank had ADB ports instead of the RJ style connector on the Mac Plus keyboard. I did have thoughts of making certain keys do things - L to turn on the lights, B for bubbles, etc.Were you able to communicate with your fish by that keyboard or did it (the fish) lack the appropriate connector/interface?
(crazy: the keyboard nowadays sells for a higher price than the Mac)