I heard one story about an octopus in a home tank who would...

I heard one story about an octopus in a home tank who would get out, cruise around the house, take knick-knacks, and drag them back to its tank. Like a dog! They're so smart that there are octopus enrichment handbooks so you don't bore your octopus. I've seen them play with Legos, Mr. Potato Head, you name it!