One of the more interesting relationships Michael Jackson had during his life was not with his famous sister, his movie star friends or other musicians, but with a tiny furry friend named Bubbles. Jackson rescued the three-year-old chimpanzee from a cancer research clinic and kept him on as a pet and friend. Bubbles famously made a cameo in the video for "Liberian Girl" and accompanied Jackson during the recording sessions for Bad. He made occasional appearances in public but generally kept to Jackson's home.
However, he did accompany Michael on a tour of Japan in 1989. In this clip, it's evident that the Bubbles is thought of as an almost-human companion (he has his own chair and is fully dressed), but also understands Jackson's sign language.
Sadly, Jackson had to move Bubbles out of his house in fear the chimp might hurt his children. Bubbles is still alive and living on a ranch in California with an animal trainer.