Spacecraft & Spycraft
A person who has been genetically modified to have four arms and hands instead of two hands and two feet. This sort of modification makes sense when the person is expected to live in a low or no gravity environment for extended periods of time.
Quaddies can stand and walk on their hindhands in up to one tenth gravity and can crawl on their four hands in up to half Earth’s gravity but are mostly immobile in a full gravity.
Quaddie musicians take full advantage of the extra hands and are quite popular in low gravity entertainment locations.