From News of the Weird:

Higher-Order Animal Research: Britain’s Sea Life Centre announced a study in July that would give octopuses Rubik’s Cubes to play with, to ascertain whether they use a certain tentacle for such activities, or any tentacle at random. [Daily Mail (London), 7-7-08]

An hour later (if memories of childhood serve correctly)…

Observers were stunned when hidden cameras filmed one octopus making off with his Rubik’s Cube into a dark corner.  Further investigation revealed his tentacles were covered in brightly colored square stickers.  “What?” he asked when questioned.  “They just came off.  I wasn’t trying to cheat!”