Black Pearl is a tiny horse who is one of nine mares owned by Nodiff Netanel's Mini Therapy Horses in the Los Angeles area. According to an article published last year in USA Today, Black Pearl is especially popular among the patients at children's hospitals due to her musical talents. As you can see in the above video, she's a talented pianist.
Here is Black Pearl performing for a child as she wakes up from anesthesia. Prank idea: don't explain the piano-playing horse to the patient. If she asks about it later, the hospital staff should claim ignorance and suggest that the patient was hallucinating.
-via David Thompson