That appears to be a Freidrich condenser of some sort (I think).
The "bowl" portion on top is designed to hold dry ice and cool water or PEG is supposed to be pumped through the coils while gas is added to the chamber via the Y fitting.
If you can sink it, you could pump CO2 into the lower fitting and use it as a ladder but It looks like the interior would not get any circulation if filled with water, so I would not advise trying it.