The Jupiter Donkey is a plastic toy used as an EEP demonstration to dramatize how the larger "surface" gravity of Jupiter would crumple a body adapted for Earth surface gravity.
The Jupiter Donkey demonstration was accompanied by the mini-tramp demonstration.
To use it, one presses the bottom part of the donkey's stand. This will remove the tension in the strings holding up its legs. Its legs will collapse. When one lets go of the button, the tension is restored.
The Jupiter Donkey was a favourite of EEP Commander Stephen Smith, who donated it, and who could often be found repeatedly activating the Donkey and laughing maniacally. During a visit in 2009-10 he requested to see it but the members could not find it anywhere. The lesson: do not store the Jupiter Donkey on top of the interlock shelves.